Full Text Available Abstract Background The degree of pulmonary hypertension is not independently related to the severity of left ventricular systolic dysfunction but is frequently associated with diastolic filling abnormalities. The aim of this study was to assess diastolic times at increasing heart rates in normal and in patients with and without abnormal exercise-induced increase in pulmonary arterypressure (PASP. Methods. We enrolled 109 patients (78 males, age 62 ± 13 years referred for exercise stress echocardiography and 16 controls. The PASP was derived from the tricuspid Doppler tracing. A cut-off value of PASP ? 50 mmHg at peak stress was considered as indicative of abnormal increase in PASP. Diastolic times and the diastolic/systolic time ratio were recorded by a precordial cutaneous force sensor based on a linear accelerometer. Results At baseline, PASP was 30 ± 5 mmHg in patients and 25 ± 4 in controls. At peak stress the PASP was normal in 95 patients (Group 1; 14 patients (Group 2 showed an abnormal increase in PASP (from 35 ± 4 to 62 ± 12 mmHg; P Conclusion The first and second heart sound vibrations non-invasively monitored by a force sensor are useful for continuously assessing diastolic time during exercise. Exercise-induced abnormal PASP was associated with reduced diastolic time at heart rates beyond 100 beats per minute.

Background. A paradoxical increase in cardiovascular events has been reported with intensively lowering diastolic blood pressure (DBP). This J-curve phenomenon has challenged the aggressive lowering of blood pressure, especially in patients with coronary artery disease. Objective. Our objective was to study the effects of low DBP on mortality and determine a threshold for which DBP should not be lowered beyond. Methods. We evaluated a two-year cross-section of primary care veteran patients, f...

Elderly female hypertensives with arterial stiffening constitute a majority of patients with heart failure with preserved ejection fraction (HFpEF), a condition characterized by inability to increase cardiac stroke volume (SV) with physical exercise. As SV is determined by the interaction between the left ventricle (LV) and its load, we wished to study the role of arterial hemodynamics for exertional SV reserve in patients at high risk of HFpEF. Twenty-one elderly (67 ± 9 yr) female hypertensive patients were studied at rest and during supine bicycle stress using echocardiography including pulsed-wave Doppler to record flow in the LV outflow tract and arterial tonometry for central arterialpressure waveforms. Arterial compliance was estimated based on an exponential relationship between pressure and volume. The ratio of aortic pressure-to-flow in early systole was used to derive characteristic impedance, which was subsequently subtracted from total resistance (mean arterialpressure/cardiac output) to yield systemic vascular resistance (SVR). It was found that patients with depressed SV reserve (NoRes; reserve reserve ?15% (Res; n = 11) showed increased compliance. Exercise produced parallel increases in LV end-diastolic volume and arterial volume in Res patients while NoRes patients exhibited a lesser decrease in SVR and a drop in effective arterial volume. Poor SV reserve in elderly female hypertensives is due to simultaneous failure of LV preload and arterial vasodilatory reserves. Abnormal arterial function contributes to a high risk of HFpEF in these patients. PMID:21926340

Full Text Available AIM: to evaluate global and segmental myocardial diastolic function, vascular wall elasticity, and the relation of arterial compliance to diastolic dysfunction in patients with SH. METHODS. We studied global and regional diastolic function of left and right ventricles (LV and RV by tissue Doppler imaging (TDI, arterial stiffness by ultrasound assessment of Young`s elastic modulus, as well as biochemical parameters in 50 middle-aged women. 14 of them were euthyroid and had endemic goiter (controls, 11 women were euthyroid but had autoimmune thyroiditis (AT, 25 patients had AT and subclinical hypothyroidism (SH. RESULTS. Patients with SH compared with euthyroid patients and controls exhibited lower Em/Am (p = 0.060 and Et/At (p = 0.034 values, increased prevalence of segmental LV diastolic dysfunction (p = 0.030 and higher Young`s elastic modulus (p = 0.049 indicating impaired global and regional diastolic function as well as increased arterial stiffness. Em/Am and Et/At ratio negatively correlated with age, TSH, LDL cholesterol values and Young`s modulus suggesting that RV and LV diastolic function was more changed in older, hypothyroid patients and by dislipidemia. Young`s elastic modulus values were positively correlated with the number of dysfunctional segments by TDI, cholesterol values and negatively with T4 values. CONCLUSIONS SH is associated with the impairment of global and regional diastolic function of RV and LV, and with increased arterial wall stiffness. There may be a common pathophysiological pathway linking these two entities. Dislipidemia and atherosclerosis acceleration can contribute, at least partly, to the cardiovascular abnormalities.

Changes in blood pressure and systolic/diastolic hypertension in Nagasaki A-bomb survivors were surveyed from 1973 to 1982. Systolic hypertension tended to decrease, while diastolic hypertension tended to increase in younger male survivors. The incidence of hypertension tended to decrease or be constant. According to the WHO classification of hypertension, the type of H, in which both diastolic and systolic blood pressures were high, and the type of SH, in which only systolic blood pressure was high, tended to decrease, while the type of DH, in which only diastolic blood pressure was high, tended to increase. (Namekawa, K.)

Relationship between occupational exposure to lead and frequency of complications in persons with arterial hypertension has been poorly investigated. This study aimed at evaluation of the relationship between occupational exposure to lead and manifestation of an increased local arterial stiffness and left ventricular diastolic dysfunction. The studies included 105 men (mean age: 44.47 ± 9.12 years) with arterial hypertension, treated with hypotensive drugs: group I - men occupationally exposed to lead (n = 53), and group II - men not exposed to lead (n = 52). In echocardiographic examination, the left ventricular diastolic dysfunction was diagnosed significantly more frequently in group I than in group II. In eTracking examination mean values of stiffness parameter (?), augmentation index (AI) and one-point pulse wave velocity (PWV-?) were significantly higher and mean values of arterial compliance (AC) were significantly lower in group I than in group II. The logistic regression showed that in the group of persons with arterial hypertension occupationally exposed to lead a more advanced age, higher blood lead concentration and higher mean values of augmentation index represent independent risk factors of left ventricular diastolic dysfunction. The multifactorial regression showed that amongst persons with arterial hypertension occupationally exposed to lead higher blood zinc protoporphyrin concentration, a more advanced age and higher value of body mass index (BMInd higher value of body mass index (BMI) represent independent risk factors of an increased local arterial stiffness. In summary, we should note that in the group of persons with arterial hypertension occupationally exposed to lead the study has demonstrated a significantly more frequent manifestation of left ventricular diastolic dysfunction and an increase in local arterial stiffness. - Highlights: ? Amongst persons with AH exposed to Pb higher ZnPP represent independent risk factor of increased local arterial stiffness. ? Higher Pb-B represent independent risk factor of left ventricular diastolic dysfunction. ? The study has demonstrated a more frequent manifestation of left ventricular diastolic dysfunction in group exposed to Pb. ? Also, in this group the study has demonstrated a more frequent manifestation of increase in local arterial stiffness.

Full Text Available Abstract Background In comparison to the well established changes in compliance that occur at the large vessel level in diabetes, much less is known about the changes in compliance of the cardiovascular system at the end-organ level. The aim of this study was therefore to examine whether there was a correlation between resistance of the intrarenal arteries of the kidney and compliance of the left ventricle, as estimated by measurements of diastolic function, in subjects with type 2 diabetes. Methods We studied 167 unselected clinic patients with type 2 diabetes with a kidney duplex scan to estimate intrarenal vascular resistance, i.e. the resistance index (RI = peak systolic velocity-minimum diastolic velocity/peak systolic velocity and a transthoracic echocardiogram (TTE employing tissue doppler studies to document diastolic and systolic ventricular function. Results Renal RI was significantly higher in subjects with diastolic dysfunction (0.72 ± 0.05 when compared with those who had a normal TTE examination (0.66 ± 0.06, p Conclusion Increasing vascular resistance of the intrarenal arteries was associated with markers of diastolic dysfunction in subjects with type 2 diabetes. These findings are consistent with the hypothesis that vascular and cardiac stiffening in diabetes are manifestations of common pathophysiological mechanisms.

"Arterial blood pressure analysis based on scattering transform I" introduces a new method based on the scattering transform for a one dimensional Schrödinger equation to reconstruct the arterial blood pressure waves and separate its systolic and diastolic parts. In this article, we propose to analyse the parameters computed from this technique in different clinical and physiological conditions. Two cases are considered: moderate chronic heart failure and high fit triathlets. The variability...

Traditional measurement and recording methods are inadequate for continuous monitoring of ambulatory pulmonary arterypressure. Therefore a new miniaturised solid state system has been developed and assessed. A manometer tipped catheter, inserted via a subclavian or cephalic vein, was used together with an isolated amplifier and peak detectors to determine systolic and diastolicpressures. Pressures were averaged over 30 seconds and stored in digital memory. After a 24 hour recording period d...

The purpose of this study was to determine the optimal systolic and diastolic time delays for electrocardiographic triggering of a non-contrast media enhanced MR angiography using a 3-dimensional fast spin echo sequence in patients suffering from peripheral arterial disease. 12 patients with suspected peripheral arterial disease were examined on a 1.5 T Philips Achieva MR scanner. A cardiac-triggered Volumetric Isotropic T2-weighted fast spin echo sequence was performed using variable trigger delays for systolic and diastolic phase. The signal in the popliteal arteries and anterior tibial arteries of the systolic and diastolic images was measured and optimal delay times for systolic and diastolic phase were determined. Minimum signal to noise ratio (SNR) appears at the time difference {Delta}T = -21 ms on systolic images of the popliteal arteries. In the anterior tibial arteries the minimum SNR is significantly higher and appears at the time difference {Delta}T = -14 ms. Diastolic delay times must be chosen as long or as short as possible depending on heart rate. In peripheral vessels triggered non-contrast MR angiography can yield results which are comparable with contrast enhanced MRA techniques. It is crucial to optimize timing parameters.

Background. A paradoxical increase in cardiovascular events has been reported with intensively lowering diastolic blood pressure (DBP). This J-curve phenomenon has challenged the aggressive lowering of blood pressure, especially in patients with coronary artery disease. Objective. Our objective was to study the effects of low DBP on mortality and determine a threshold for which DBP should not be lowered beyond. Methods. We evaluated a two-year cross-section of primary care veteran patients, from 45 to 85 years of age. Receiver operating characteristics (ROC) were employed to establish an optimal cut-off point for DBP. Propensity-score matching and multivariate logistic regression were used to control for confounders. All-cause mortality was the primary outcome. Results. 14,270 patients were studied. An ROC curve found a threshold value of DBP 70?mmHg had the greatest association with mortality (P < 0.001). 49% of patients had a DBP of 70?mmHg or less. Using a propensity-matched multivariate logistic regression, odds ratio for all-cause mortality in subjects with a DBP less than 70?mmHg was 1.5 (95% CI 1.3-1.8). Conclusions. Reduction of DBP below 70?mmHg is associated with increased all-cause mortality. Hypertension guidelines should include a minimum blood pressure target. PMID:23606946

Systolic and diastolic blood pressure, pulse pressure (PP), and body mass index (BMI) are heritable traits in human metabolic health but their common genetic and environmental backgrounds are not well investigated. The aim of this article was to explore the phenotypic and genetic associations among PP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. The studied sample contained 615 twin pairs (17–84 years) collected in the Qingdao municipality. Univariate and multivariate structural equation models were fitted for assessing the genetic and environmental contributions. The AE model combining additive genetic (A) and unique environmental (E) factors produced the best fit for each four phenotypes. Heritability estimated in univariate analysis ranged from 0.42 to 0.74 with the highest for BMI (95% CI 0.70–0.78), and the lowest for PP (95% CI 0.34–0.49). The multivariate model estimated (1) high genetic correlations for DBP with SBP (0.87), PP with SBP (0.75); (2) low–moderate genetic correlations between PP and DBP (0.32), each BP component and BMI (0.24–0.37); (3) moderate unique environmental correlation for PP with SBP (0.68) and SBP with DBP (0.63); (4) there was no significant unique environmental correlation between PP and BMI. Overall, our multivariate analyses revealed common genetic and environmental backgrounds for PP, BP, and BMI in Chinese twins.

Arterial stiffness, blood pressure (BP) and blood lipids may be improved by milk in adults and the effects may be mediated via proteins. However, limited is known about the effects of milk proteins on central aortic BP and no studies have examined the effects in children. Therefore, the present trial examined the effect of milk and milk proteins on brachial and central aortic BP, blood lipids, inflammation and arterial stiffness in overweight adolescents. A randomised controlled trial was conducted in 193 overweight adolescents aged 12–15 years. They were randomly assigned to drink 1 litre of water, skimmed milk, whey or casein for 12 weeks. The milk-based test drinks contained 35 g protein/l. The effects were compared with the water group and a pretest control group consisting of thirty-two of the adolescents followed 12 weeks before the start of the intervention. Outcomes were brachial and central aortic BP, pulse wave velocity and augmentation index, serum C-reactive protein and blood lipids. Brachial and central aortic diastolic BP (DBP) decreased by 2·7% (P = 0·036) and 2·6%(P = 0·048), respectively, within the casein group and the changes were significantly different from those of the pretest control group (P = 0·040 and P = 0·034, respectively). There was a significant increase in central aortic DBP, and in brachial and central systolic BP in the whey group compared with the water group (P = 0·003, P = 0·009 and P = 0·002, respectively). There were no changes in measures of arterial stiffness or blood lipid concentrations. A high intake of casein improves DBP in overweight adolescents. Thus, casein may be beneficial for younger overweight subjects in terms of reducing the longterm risk of CVD. In contrast, whey protein seems to increase BP compared with drinking water; however, water may be considered an active control group.

Arterial stiffness, blood pressure (BP) and blood lipids may be improved by milk in adults and the effects may be mediated via proteins. However, limited is known about the effects of milk proteins on central aortic BP and no studies have examined the effects in children. Therefore, the present trial examined the effect of milk and milk proteins on brachial and central aortic BP, blood lipids, inflammation and arterial stiffness in overweight adolescents. A randomised controlled trial was conducted in 193 overweight adolescents aged 12–15 years. They were randomly assigned to drink 1 litre of water, skimmed milk, whey or casein for 12 weeks. The milk-based test drinks contained 35 g protein/l. The effects were compared with the water group and a pretest control group consisting of thirty-two of the adolescents followed 12 weeks before the start of the intervention. Outcomes were brachial and central aortic BP, pulse wave velocity and augmentation index, serum C-reactive protein and blood lipids. Brachial and central aortic diastolic BP (DBP) decreased by 2·7% (P= 0·036) and 2·6% (P = 0·048), respectively, within the casein group and the changes were significantly different from those of the pretest control group (P = 0·040 and P = 0·034, respectively). There was a significant increase in central aortic DBP, and in brachial and central systolic BP in the whey group compared with the water group (P = 0·003, P= 0·009 and P = 0·002, respectively). There were no changes in measures of arterial stiffness or blood lipid concentrations. A high intake of casein improves DBP in overweight adolescents. Thus, casein may be beneficial for younger overweight subjects in terms of reducing the longterm risk of CVD. In contrast, whey protein seems to increase BP compared with drinking water; however, water may be considered an active control group.

Full Text Available "nBackground: Direct monitoring of arterialpressure using a transducer system is not affordable in most operating rooms and ICU wards in Iran. It is, however, possible to use an aneroid manometer instead, but it is not standardized yet, nor studied enough; and its measurements may not be interpretable. "nMethods: To study the correlation of the arterialpressure readings between a manometer and a transducer system, systolic and diastolicarterialpressure was measured 105 times using both systems via arterial cannulation in seven patients during surgery. Mean arterialpressure was directly recorded in the transducer system, while it was calculated in the manometer system. In the manometer system, the extension tube was filled with saline halfway from the patient and the other empty end was connected to a manometer. The transducer and the air-fluid interface in the extension tube were positioned at same level. Correlation of the arterialpressures between the systems was tested using linear regression and Pearson correlation. "nResults: Mean arterialpressure differed by 2 (1-3 mmHg [mean (CI 95%] between the systems, however, pulse pressure was lower in the manometer system by 37 (33-41 mmHg. The mean arterialpressure in the transducer system (MAPT correlated well and linearly with the systolic arterialpressure in the manometer system (SAPM by R=0.966. Therefore, MAPT can be regarded as a function of SAPM through the following formula: MAPT = (1.03 ´ SAPM - 7.34. "nConclusion: The mean arterialpressure in the transducer system can be reliably estimated by monitoring the systolic arterialpressure in the manometer system.

Measurements of arterial diameter during the cardiac cycle are increasingly used to study the mechanical properties of the arterial wall and changes associated with disease. In this paper, diastolic and systolic diameters of the carotid arteries were estimated from ultrasound imaging using the following three different procedures: a/ B-mode imaging with region tracking and block-matching, b/ M-mode imaging with automated edge detection and c/ automatic segmentation of the arterial lumen at diastole and systole using the Hough transform. Transverse images of the carotid artery were used, in which the arterial lumen has an almost circular appearance. The values for systolic and diastolic diameters estimated with the Hough transform, 0.69±0.04 and 0.61±0.06, respectively, were closer to those estimated with B-mode and motion tracking, 0.75±0.07 and 0.67±0.09. A large difference was found for a subject with an atherosclerotic vessel wall. It is concluded that the Hough transform can be efficiently used to automatically segment healthy arterial wall lumen from B-mode ultrasound images of the carotid artery, assuming a circular shape. In atherosclerotic vessel walls the assumption for circular shape may no longer be valid, and thus the use of an elliptical shape may be more appropriate. PMID:17282555

The appearance of cardiovascular events when the diastolic blood pressure is lowered to some critical level is referred to as a "J-curve." Extensive data document the presence of a J-curve appearing when the diastolic blood pressure is lowered by antihypertensive medication to a level below 65 mm Hg, particularly in patients with underlying coronary heart disease even if such disease has not been clinically evident. Caution is needed in the more intensive and widespread treatment of hypertensive patients to avoid a J-curve. PMID:21845442

Oscillometric blood pressure devices tend to overestimate systolic blood pressure and underestimate diastolic blood pressure compared with sphygmomanometers. Recent studies indicate that discrepancies in performance between these devices may differ between healthy and diabetic subjects. Arterial stiffness in diabetics could be the underlying factor explaining these differences. We studied differences between a Dinamap ...

Full Text Available The purpose of the study was to find out the effect of gender difference and circadian rhythm on diastolic blood pressure for volleyball players. METHODS: To achieve the purpose, a total of thirty volleyball players [men (n = 15 and women (n = 15] age between 19 years and 22 years from Einstein College of Engineering, Tamil Nadu, India were selected as subjects. The two independent variables of gender and circadian variations and dependent variable of diastolic blood pressure were selected for this study. The experimental design used was static group factorial design. The data were collected at 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 hours on diastolic blood pressure by using Erkameter during the academic year of 2009 – 2010. Collected data were subjected to statistical analysis by using two-way factorial (2 x 6 Analysis of Variance (ANOVA and Cosinor analysis. RESULTS: There was insignificant difference between genders, significant difference at different times of the day and insignificant circadian rhythmicity exists on diastolic blood pressure for women and significant for men. CONCLUSION: It is recommended to the physical educators to adopt the findings of this study while planning to improve sports skills for the players and athletes.

The results of several large studies of hypertension and follow up studies on insured people have indicated that the lower the blood pressure the better for longevity. These studies excluded subjects with overt ischaemia. More recently long term studies of hypertension that included patients with more severe forms of hypertension and did not exclude those with overt ischaemia have shown a J shaped relation between diastolic blood pressure during treatment and myocardial infarction; the lowest...

Calcineurin is a Ca2+/calmodulin-dependent protein phosphatase that induces myocardial growth in response to several physiological and pathological stimuli. Calcineurin inhibition, induced either via cyclosporine or genetically, can decrease myocardial hypertrophy secondary to pressure overload without affecting left ventricular (LV) systolic function. Since hypertrophy can also affect LV diastolic function, the goal of this study was to examine the effects of chronic pressure overload (2 wk ...

Resting first-pass radionuclide angiocardiography (RNA) was used to derive left-ventricular (LV) peak diastolic filling rates (PFR) in normals (Group 1:N . 12) and in patients with coronary artery disease (CAD), both without (Group 2:N . 27) and with previous myocardial infarction (Group 3:N . 23). Resting peak filling rates were significantly depressed in both Group 2 (1.61 +/- 0.36; p less than 0.01) and Group 3 (1:35 +/- 0.26; p less than 0.001) patients when compared with Group 1, normals (2.14 +/- 0.63). Even though LV systolic function of Group 2 patients was normal and comparable to that in Group 1 (EF . 0.55 +/- 0.06 against EF 0.55 +/- 0.06 NS), diastolic dysfunction [PFR less than 1.61 end diastolic volume/sec (EDV/sec)] was present at rest in 14 of 27 (52%). Depressed PFR values was also seen in 20 of 23 Group 3 patients (87%). It appears that (a) resting PFR is a sensitive and easily obtainable parameter of the diastolic dysfunction associated with CAD; (b) abnormal PFR values are seen in almost all patients with previous myocardial damage, and (c) a significant proportion of CAD patients without any evidence of abnormal systolic function have depressed resting PFR of the LV

OBJECTIVE: To determine the accuracy of using systolic and diastolic blood pressure, mean arterialpressure, and increase of blood pressure to predict pre-eclampsia. DESIGN: Systematic review with meta-analysis of data on test accuracy. DATA SOURCES: Medline, Embase, Cochrane Library, Medion, checking reference lists of included articles and reviews, contact with authors. Review methods Without language restrictions, two reviewers independently selected the articles in which the accuracy of b...

Isolated systolic hypertension is a major health burden that is expanding with the aging of our population. There is evidence that central arterial stiffness contributes to the rise in systolic blood pressure (SBP); at the same time, central arterial stiffening is accelerated in patients with increased SBP. This bidirectional relationship created a controversy in the field on whether arterial stiffness leads to hypertension or vice versa. Given the profound interdependency of arterial stiffness and blood pressure, this question seems intrinsically challenging, or probably naïve. The aorta's function of dampening the pulsatile flow generated by the left ventricle is optimal within a physiological range of distending pressure that secures the required distal flow, keeps the aorta in an optimal mechanical conformation, and minimizes cardiac work. This homeostasis is disturbed by age-associated, minute alterations in aortic hemodynamic and mechanical properties that induce short- and long-term alterations in each other. Hence, it is impossible to detect an "initial insult" at an epidemiological level. Earlier manifestations of these alterations are observed in young adulthood with a sharp decline in aortic strain and distensibility accompanied by an increase in diastolic blood pressure. Subsequently, aortic mechanical reserve is exhausted, and aortic remodeling with wall stiffening and dilatation ensue. These two phenomena affect pulse pressure in opposite directions and different magnitudes. With early remodeling, there is an increase in pulse pressure, due to the dominance of arterial wall stiffness, which in turn accelerates aortic wall stiffness and dilation. With advanced remodeling, which appears to be greater in men, the effect of diameter becomes more pronounced and partially offsets the effect of wall stiffness leading to plateauing in pulse pressure in men and slower increase in pulse pressure (PP) than that of wall stiffness in women. The complex nature of the hemodynamic changes with aging makes the "one-size-fits-all" approach suboptimal and urges for therapies that address the vascular profile that underlies a given blood pressure, rather than the blood pressure values themselves. PMID:25687599

For three decades we followed up for longevity indicators, including diet, arterial blood pressure, and body mass index 379 mobile, long-living persons from Croatia, now aged 70 to 92 years, of whom 167 men aged (78.6 ± 4.0) years and 212 women aged (77.9 ± 4.1) years. One hundred and ninety-five were from the continental and 184 from the coastal Croatia. The participants were examined in 1972, 1982, and again in 2006/7. Changes in body mass index (BMI), arterial blood pressure (ABP), and in answers to our Food Frequency Questionnaire about dietary habits were analysed using log-linear models. Over the last 24 years of aging (age 55 to 78 years) the subjects showed a statistically significant decrease in body mass and height and a significant increase in the systolic blood pressure. Diastolic blood pressure and BMI showed no significant changes over this period. Consumption of preserved and fresh meat, bread, and starch (potato, pastry and rice) dropped significantly with age, while the consumption of fish, fresh and cooked vegetables, fruit, and dairy products significantly increased. These dietary changes were not associated with changes in the systolic and diastolic ABP. About 80 % were overweight (BMI >25 kg m(-2)) throughout the follow-up, even though their body mass dropped significantly after the age of 55. However, their survival suggests that BMI may not be the best indicator of longevity or healthy aging. PMID:22548847

Five-year observations yielded diurnal profiles of arterialpressure (AP) in practically healthy residents of the north of Tyumen region. Their analysis revealed the enhancement of AP variability in day- and nighttime (especially diastolic AP), elevated rise of morning AP in the absence of adequate decrease of nocturnal AP. PMID:25269193

Tortuosity that often occurs in carotid and other arteries has been shown to be associated with high blood pressure, atherosclerosis, and other diseases. However the mechanisms of tortuosity development are not clear. Our previous studies have suggested that arteries buckling could be a possible mechanism for the initiation of tortuous shape but artery buckling under pulsatile flow condition has not been fully studied. The objectives of this study were to determine the artery critical buckling pressure under pulsatile pressure both experimentally and theoretically, and to elucidate the relationship of critical pressures under pulsatile flow, steady flow, and static pressure. We first tested the buckling pressures of porcine carotid arteries under these loading conditions, and then proposed a nonlinear elastic artery model to examine the buckling pressures under pulsatile pressure conditions. Experimental results showed that under pulsatile pressurearteries buckled when the peak pressures were approximately equal to the critical buckling pressures under static pressure. This was also confirmed by model simulations at low pulse frequencies. Our results provide an effective tool to predict artery buckling pressure under pulsatile pressure. PMID:22356844

Blood pressure measurements recorded during the medical Research Council's treatment trial for mild hypertension have been analysed according to the calendar month in which the readings were made. For each age, sex, and treatment group systolic and diastolicpressures were higher in winter than in summer. The seasonal variation in blood pressure was greater in older than in younger subjects and was highly significantly related to maximum and minimum daily air temperature measurements but not ...

Heart and Artery Damage and High Blood Pressure Updated:Sep 11,2014 There are several harmful consequences for your arteries and ... the arteries? HBP damages the walls of the arteries. If you have high blood pressure, the force ...

Tortuosity that often occurs in carotid and other arteries has been shown to be associated with high blood pressure, atherosclerosis, and other diseases. However the mechanisms of tortuosity development are not clear. Our previous studies have suggested that arteries buckling could be a possible mechanism for the initiation of tortuous shape but artery buckling under pulsatile flow condition has not been fully studied. The objectives of this study were to determine the artery critical bucklin...

To assess the effectiveness of femoral and radial arterial lines on the correlation of peripheral and central mean arterial blood pressure in children after discontinuation of cardiopulmonary bypass. Fifty children scheduled for cardiac surgery with cardiopulmonary bypass were included in the study. After approval from the hospital ethics committee and informed consent. 50 children undergoing cardiac surgical procedures with cardiopulmonary bypass were randomly assigned to two different groups. In Group- A (RAP, n-2) a radial arterial line and in Group-B (FAP, n-25) a femoral arterial line was used to monitor the blood pressure. Simultaneous mean peripheral arterialpressure and mean central aortic pressure were recorded before cardiopulmonary bypass and 5 mins after separation from the cardiopulmonary bypass. The correlation of mean peripheral arterialpressure (radial and femoral) versus mean aortic pressure were compared. The data was recorded as Mean +- SD and P-value. The ages of children ranged from 4-12 years and their weight from 14.1-28.5 kg. In all of them following cardiopulmonary bypass, aortic pressure correlates better with femoral arterialpressure (p<0.001). The radial arterial line readings under estimated central aortic pressure when compared to femoral arterial line readings. Aortic pressure readings correlate better with femoral arterialpressure than radial arterialpressure in children. (author)

S2-gated equilibrium scintigraphs were made for a control group (5 subjects ) and a patient group (21 subjects) with mild coronary artery disease and LVEF greater than 50% at rest. Four LV diastolic phase indices (PEAK, PEAK TIME, SHIFT, and R-RATIO) were derived from the scintigraphs as follows. The deviation of the disastolic phase volume curve from the SIN curve was used as an early diastolic phase index. The PEAK measures the maximum deviation; the PEAK TIME measures the time from the start of diastole to the PEAK; the SHIFT measures the phase deviation between the two curves at the mid-point of diastole. As an index of left atrial systolic function, the ratio of the deviation area of the early diastolic phase (R) to the deviation area of the early plus the late diastolic phases (R+A) was derived and referred to as the R-RATIO [(R/(R+A)]. The cardiac reserve was then evaluated from these four indicies.The patient group was further divided into an LVEF increase group and an LVEF decrease group according to the results of an exercise test. No difference was found in the systolic and diastolic functions between the control group and the increase group leading us to consider that their LV functions are identical. The decrease group, when compared to the control and increase groups, was found to have a rapid filling phase dysfunction which was compensated by the left atrial systolic function. From the use of these new diastolic phase indices in the above anaw diastolic phase indices in the above analysis, a slight decrease in the cardiac reserve of patients with mild coronary artery disease was observed for the systolic function during exercise. (author)

The topic of the J-curve relationship between blood pressure and coronary artery disease (CAD) has been the subject of much controversy for the past decades. An inverse relationship between diastolicpressure and adverse cardiac ischemic events (i.e., the lower the diastolicpressure the greater the risk of coronary heart disease and adverse outcomes) has been observed in numerous studies. This effect is even more pronounced in patients with underlying CAD. Indeed, a J-shaped relationship between diastolicpressure and coronary events was documented in treated patients with CAD in most large trials that scrutinized this relationship. In contrast to any other vascular bed, the coronary circulation receives its perfusion mostly during diastole; hence, an excessive decrease in diastolicpressure can significantly hamper perfusion. This adverse effect of too low a diastolicpressure on coronary heart disease leaves the practicing physician with the disturbing possibility that, in patients at risk, lowering blood pressure to levels that prevent stroke or renal disease might actually precipitate myocardial ischemia. However, these concerns should not deter physicians from pursuing a more aggressive control of hypertension, because currently blood pressure is brought to recommended target levels in only approximately one-third of patients. PMID:19892233

Right ventricular systolic and diastolic function was studied in patients with ischemic heart disease using equilibrium radionuclide ventriculography. In patients with inferior myocardial infarction and proximal right coronary lesions, the right ventricular ejection fraction (0.43+-0.06, n=10, mean+-SD) and peak filling rate (1.7+-0.4 EDV/sec) were lower than normals (0.57+-0.07 and 2.7+-0.4 EDV/sec, n=10, p<0.001, respectively). In these patients, the right ventricular time to peak filling rate was longer than in normals (225+-36 msec vs 136+-45 msec, p<0.001), while the left ventricular ejection fraction remained normal. In patients with inferior myocardial infarction and distal right coronary lesions, the right ventricular ejection fraction, peak filling rate and time to peak filling rate were not different from those in normals. Even in patients with proximal right coronary lesions, the right ventricular ejection fraction was normal unless they had an inferior myocardial infarction. A decreased left ventricular ejection fraction and abnormal motion of the ventricular septum did not affect the right ventricular ejection fraction. The present results suggest that patients with an inferior myocardial infarction and proximal right coronary lesion often develop right ventricular systolic and diastolic dysfunction. (author)

Full Text Available Abstract Background New sensors for intelligent remote monitoring of the heart should be developed. Recently, a cutaneous force-frequency relation recording system has been validated based on heart sound amplitude and timing variations at increasing heart rates. Aim To assess sensor-based post-exercise contractility, diastolic function and pressure in normal and diseased hearts as a model of a wireless telemedicine system. Methods We enrolled 150 patients and 22 controls referred for exercise-stress echocardiography, age 55 ± 18 years. The sensor was attached in the precordial region by an ECG electrode. Stress and recovery contractility were derived by first heart sound amplitude vibration changes; diastolic times were acquired continuously. Systemic pressure changes were quantitatively documented by second heart sound recording. Results Interpretable sensor recordings were obtained in all patients (feasibility = 100%. Post-exercise contractility overshoot (defined as increase > 10% of recovery contractility vs exercise value was more frequent in patients than controls (27% vs 8%, p 1 in 20 patients and in none of the controls (p 1 in only 3 patients (p Conclusion Post-exercise contractility, diastolic time and pressure changes can be continuously measured by a cutaneous sensor. Heart disease affects not only exercise systolic performance, but also post-exercise recovery, diastolic time intervals and blood pressure changes – in our study, all of these were monitored by a non-invasive wearable sensor.

Full Text Available A partir de la quinta o sexta décadas de la vida, la hipertensión arterial adopta formas y obedece a causas diferentes a las del niño o a las del adulto joven. En este caso, la presión arterial sistólica aumenta (> 140 mmHg y la diastólica se mantiene o disminuye (From the fifth or sixth decades of life, high blood pressure adopts ways and is due to different causes to that of child or to that of young adult. In this case, systolic arterialpressure increases (> 140 mmHg, and the diastolic one remains or decreases (< 90 mmHg, and differential pressure increases. The cause is conduction artery stiffness by atherosclerosis as well as the action of some hormones including: adrenaline, noradrenaline, agiotensin II, and aldosterone on the arterial medium wall. Diagnosis is made verifying presence of an isolated systolic high blood pressure in patients aged over 50. In youngest, in addition to high systolic pressure with a normal or low diastolicpressure, it is advisable measurement of others indicators of aortic stiffness. Systolic pressure in third age may to be associated with: left ventricular and arterial hypertrophy, a relaxation decrease of cardiac and coronary walls, myocardial ischemia, nephroesclerosis, cognitive decline or even dementia. Treatment requires special cares and must to adjust to the frequent morbidity of old age. The more effective antihypertensive groups according to randomized assays include: agiotensin-converting enzyme (ACE inhibitors, agiotensin II blockers, aldosterone antagonists, and calcium blockers. Nitrates and diuretic agents have been used to reduce systolic pressure, especially when there is an aortic valvular regurgitation. Decrease of systolic pressure to result in a delay or an arrest of cardiovascular complications, of cognitive decline, and dementia in third age patients.

Full Text Available The research goal is to carry on the comparative analysis of medicines of various chemical structure, Telmisar-tan and Bisoprolol, and to reveal their effect on the arterial blood pressure level and the indices of various metabolic processes in patients with arterial hypertension. 60 out-patients with arterial hypertension (stage II risk III both males and females aged 33-55 have been under study taking Telmisartan and Bisoprolol for 3 months. While treating the patients the arterial blood pressure level control and biochemical investigations for determination the indices of metabolic processes have been carried out. The investigated medications have provided the decrease of systolic and diastolicarterialpressure parameters, the increase of concentration of total and ionized calcium, chlorine ions, urea and total bilirubin in blood plasma. Therapy with Telmisartan has shown more significant increase of potassium level in erythro-cytes, decrease of levels of natrium, glucose, glycolized hemoglobin and triglycerides and increased contents of alani-naminotransferase and aspartataminotransferase. The course of therapy with Bisoprolol has restored the normal level of magnesium in blood plasma, has not have any influence on carbohydrate and lipid metabolism, increased the level of alaninaminotransferase and significantly increased the contents of total and ionized calcium, urea and creatinine. 3-months therapy with Telmisartan and Bisoprolol has proved the decrease of systolic and diastolicarterialpressure in patients with arterial hypertension. The medications under study have had active and variable effects on metabolic indices

Aortic blood pressure (BP) and 24-h ambulatory BP are both better associated with target organ damage than office brachial BP. However, it remains unclear whether a combination of these two techniques would be the optimal methodology to evaluate patients' BP in terms of left ventricular diastolic dysfunction (LVDD) prevention. In 230 participants, office brachial and aortic BPs were measured by a validated BP monitor and a tonometry-based device, respectively. 24-h ambulatory brachial and aortic BPs were measured by a validated ambulatory BP monitor (Mobil-O-Graph, Germany). Systematic assessment of patients' LVDD was performed. After adjustment for age, gender, hypertension and antihypertensive treatment, septum and lateral E/Ea were significantly associated with office aortic systolic BP (SBP) and pulse pressure (PP) and 24-h brachial and aortic SBP and PP (P?0.04), but not with office brachial BP (P?0.09). Similarly, 1 standard deviation in SBP was significantly associated with 97.8±20.9, 86.4±22.9, 74.1±23.3 and 51.3±22.6 in septum E/Ea and 68.6±20.1, 54.2±21.9, 37.9±22.4 and 23.1±21.4 in lateral E/Ea, for office and 24-h aortic and brachial SBP, respectively. In qualitative analysis, except for office brachial BP, office aortic and 24-h brachial and aortic BPs were all significantly associated with LVDD (P?0.03), with the highest odds ratio in 24-h aortic SBP. Furthermore, aortic BP, no matter in the office or 24-h ambulatory setting, showed the largest area under receiver operating characteristic curves (P?0.02). In conclusion, 24-h aortic BP is superior to other BPs in the association with LVDD. PMID:25391758

Full Text Available To measure precise blood pressure (BP and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.

Full Text Available Background: Left ventricular end diastolicpressure could be estimated collectively using various measures of mitral valve and pulmonary venous flow velocities. In patients with aortic regurgitation, the AR velocity reflects the diastolicpressure difference between the aorta and the left ventricle. We sought to predict the left ventricular end diastolicpressure by a new Doppler index as aortic regurgitation peak early to late diastolicpressure gradient ratio.Patients and Methods: Fifty three patients with at least moderate aortic regurgitation were enrolled in this study. Physical examination, electrocardiography and echocardiography were performed one day before cardiac catheterization. The severity of AR was graded according to the recommendations of American society for echocardiography. The pressure half time, aortic regurgitation early diastolic velocity , aortic regurgitation early diastolicpressure gradient , aortic regurgitation end diastolic velocity, aortic regurgitation end diastolicpressure gradient, and early diastolic to end diastolicpressure gradient ratio of averaged three beats were measured and recorded. The results from cardiac catheterization and echocardiography were compared.Result: The early diastolic to end diastolicpressure gradient ratio was very accurate (80% for determining the left ventricular end diastolicpressure (P =0.01. An early diastolic to end diastolicpressure gradient ratio of 1.5 has a sensitivity of 96% and a specificity of 32% for left ventricular end diastolicpressure ?12 mmHg. The best cutoff value of early diastolic to end diastolicpressure gradient ratio for the prediction of left ventricular end diastolicpressure >12 mmHg was higher than 2.0, with a sensitivity of 71% and specificity of 96% We found no significant correlation between the left ventricular end diastolicpressure with either left ventricular ejection fraction or aortic regurgitation severity in cardiac catheterization (P =0.5.Conclusion: Doppler echocardiography is a viable alternative of cardiac catheterization for determination of the left ventricular end diastolicpressure. The early diastolic to end diastolicpressure gradient ratio is a simple, easy and new method for assessment of the LVEDP in patients with severe chronic aortic regurgitation.

Background. The use of echocardiography in intensive care settings impacts decision making. A prerequisite for the use of echocardiography is relative resistance to changes in volume status and levels of positive pressure ventilation (PPV). Studies on indices of diastolic function report conflicting results with regard to dependence on volume status. Evidence is scarce on PPV. Methods. Ten healthy subjects were exposed to 6 levels of positive end-expiratory pressure (PEEP) and pressure support (PS) following a baseline reading. All ventilator settings were performed at three positions: horizontal, reverse-Trendelenburg, and Trendelenburg. Echocardiography was performed throughout. Results. During spontaneous breathing, early diastolic transmitral velocity (E) changed with positioning (P <0.001), whereas early diastolic velocity of the mitral annulus (e') was independent (P = 0.263). With PPV, E and e' proved preload dependent (P ??values <0.001). Increases in PEEP, PS, or a combination influenced E and e' in reverse-Trendelenburg- and horizontal positions, but not in the Trendelenburg position. Discussion. The change towards preload dependency of e' with PPV suggests that PPV increases myocardial preload sensitivity. The susceptibility of E and e' to preload changes during PPV discourages their use in settings of volume shifts or during changes in ventilator settings. Conclusion. Positioning and PPV affect E and e'.

To determine the effects of verapamil on left ventricular (LV) systolic function and diastolic filling in patients with coronary artery disease (CAD), researchers performed gated radionuclide angiography at rest and during exercise in 16 symptomatic patients before and during oral verapamil therapy (480 mg/day). Twelve patients were also studied during oral propranolol. LV ejection fraction at rest was normal in 13 patients, but abnormal diastolic filling at rest, defined as peak filling rate (PFR) less than 2.5 end-diastolic volumes (EDV)/sec or time to PFR greater than 180 msec, was present in 15. During verapamil, resting ejection fraction decreased, but resting diastolic filling improved: PFR increased and time to PFR decreased. Exercise ejection fraction did not change during verapamil, but exercise PFR increased, and exercise time to PFR decreased. In contrast, propranolol did not alter ejection fraction, PFR, or time to PFR at rest or during exercise. Thus, LV ejection fraction is decreased by verapamil at rest but is unchanged during exercise. While LV systolic function is not improved by verapamil, LV diastolic filling is enhanced by verapamil, both at rest and during exercise. These mechanisms may account in part for the symptomatic improvement in many patients during verapamil therapy

Individual studies of stroke have not clearly answered two questions: on the relation, if any, between total blood cholesterol and stroke; and on how the strength of the relation between diastolic blood pressure and stroke varies with age. The associations of blood cholesterol and diastolic blood pressure with subsequent stroke rates were investigated by review of 45 prospective observational cohorts involving 450,000 individuals with 5-30 years of follow-up (mean 16 years, total 7.3 million ...

Full Text Available Abstract Background The aim of this study was to determine if hypertensive type 2 diabetic patients, when compared to patients with essential hypertension have an increased left ventricular mass index (LVMI and a worse diastolic function, and if this fact would be related to 24-h pressoric levels changes. Methods Ninety-one hypertensive patients with type 2 diabetes mellitus (DM (group-1 [G1], 59 essential hypertensive patients (group-2 [G2] and 26 healthy controls (group-3 [G3] were submitted to 24-h Ambulatory Blood Pressure Monitoring (ABPM and echocardiography (ECHO with Doppler. We calculated an average of fasting blood glucose (AFBG values of G1 from the previous 4.2 years and a glycemic control index (GCI (percentual of FBG above 200 mg/dl. Results G1 and G2 did not differ on average of diurnal systolic and diastolic BP. However, G1 presented worse diastolic function and a higher average of nocturnal systolic BP (NSBP and LVMI (NSBP = 132 ± 18 vs 124 ± 14 mmHg; P 2; P 165 mg/dl showed an additional risk of LVH (P Conclusion This study suggests that hyperglycemia and higher NSBP levels should be responsible for an increased prevalence of LVH in hypertensive patients with Type 2 DM.

Citrus paradisi (grapefruit) consumption is considered as beneficial and it is popularly used for the treatment of a vast array of diseases, including hypertension. In the present study, the coronary vasodilator and hypotensive effects of Citrus paradisi peel extract were assessed in the Langendorff isolated and perfused heart model and in the heart and lung dog preparation. In both models, Citrus paradisi peel extract decreased coronary vascular resistance and mean arterialpressure when compared with control values (60 +/- 15 x 10(7) dyn s cm(-5) vs 100 +/- 10 x 10(7) dyn s cm(-5) and 90 mmHg vs 130 +/- 15 mmHg, respectively). These decreases in coronary vascular resistance and mean arterialpressure were blocked when isolated and perfused hearts and mongrel dogs were pre-treated with L-NAME. In humans, Citrus paradisi juice decreased diastolicarterialpressure and systolic arterialpressure both in normotensive and hypertensive subjects. Citrus paradisi juice produced a greater decrease in mean arterialpressure when compared with Citrus sinensis juice, cow milk and a vitamin C-supplemented beverage. However, more detailed studies are required to isolate, purify and evaluate the chemical compounds responsible for this pharmacological effect and to clarify its possible role for treating hypertension. PMID:19153985

Full Text Available Thyroid disorder is very common in Pakistani population and most of the patients either sex having thyroid problems which may disturb various body systems for example variation in systolic / diastolic blood pressure, pulse rate, serum creatinine level and ALT / SGPT (Alanine Aminotransferase and AST / SGOT (Aspartate Aminotransferase levels. The purpose of our study is to determine the effects of thyroid dysfunction on blood pressure, pulse rate, renal and liver functions and there correlation with thyroid status before and after treatment in patients with hypo and hyperthyroidism respectively. The results showed that there are significant differences in the levels of biochemical parameters (Serum Creatinine, ALT, AST, FT3, FT4 and TSH as compared to normal in both groups. Significant changes were also found in blood pressure and pulse rate of both male and female groups.

A new method for analyzing arterial blood pressure is presented in this report. The technique is based on the scattering transform and consists in solving the spectral problem associated to a one-dimensional Schr\\"odinger operator with a potential depending linearly upon the pressure. This potential is then expressed with the discrete spectrum which includes negative eigenvalues and corresponds to the interacting components of an N-soliton. The approach is similar to a nonlinear Fourier transform where the solitons play the role of sine and cosine components. The method provides new cardiovascular indices that seem to contain relevant physiological information. We first show how to use this approach to decompose the arterial blood pressure pulse into elementary waves and to reconstruct it or to separate its systolic and diastolic phases. Then we analyse the parameters computed from this technique in two physiological conditions, the head-up 60 degrees tilt test and the isometric handgrip test, widely used for...

Percutaneous Transluminal Angioplasty (PTA) is an effective initial treatment modality in renovascular hypertension. For determination of PTA effect, the pulse pressure recording of renal artery is not simple as compared with in femoral artery stenosis. We tried to evaluate the PTA effect of renal artery stenosis with tracing the pressure of distal renal artery. We used the cardiac catheterization apparatus (VR-12 Honeywell) as a pressure monitor in two cases of focal renal arterial stenosis. The renal arterypressure was doubled after first attempt of ballooning, and the pressure elevated up to 94% and 79% of aorta pressure in two cases, respectively, after third attempt. We believe that renal arterypressure monitoring is a good method of determination of PTA effect in renovascular hypertension.

Arterial volume clamping uses external compression of an artery to provide continuous non-invasive measurement of arterial blood pressure. It has been assumed that mean arterialpressure (MAP) corresponds to the point where unloading leads to the maximum oscillation of the arterial wall as reflected by photoplethysmogram (PPG), an assumption that has been challenged. Five subjects were recruited for the study (three males, mean age (SD) = 32 (15) years). The PPG waveform was analysed to identify the relationship between the external compressing pressure, PPG pulse amplitude and MAP. Two separate tests were carried out at compression step intervals of 10?mmHg and 2?mmHg, respectively. No significant differences were found between the two tests. The bias between the compressing pressure and the MAP was -4.7?±?5.63?mmHg (p?distribution. Further research is needed to identify optimal algorithms for estimation of MAP using PPG associated with arterial compression. PMID:25429784

Hypertension is a risk factor for accelerated saphenous vein (SV) graft disease and endothelial dysfunction in a number of vascular territories. We examined the relationship between blood pressure (BP) and vascular function in SV from 94 male patients undergoing coronary artery bypass grafting (CABG). Patients were pretreated with respect to cholesterol (3.4±1.2 mmol/L) and BP (systolic 139±22 mmHg, diastolic 74±13 mmHg). All patients were taking aspirin, 85% statins, 50% angiotensin-converting enzyme inhibitors and 70% beta-blockers. We demonstrate in human SV rings ex vivo that increased BP has no effect on acetylcholine-mediated vasodilatation (p=0.58), nor on the constrictor response to L-NMMA (p=0.98), but has a positive association with the constrictor response to phenylephrine (p=0.008) and a negative correlation with the vasodilator response to sodium nitroprusside (p=0.03). These results may provide further explanation for the high incidence of early vein graft failure after CABG in hypertensive patients and support an aggressive approach to optimize BP before surgery. PMID:24963039

Despite the growing number of patients affected, the understanding of diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF) is still poor. Clinical trials, largely based on successful treatments for systolic heart failure, have been disappointing, suggesting that HFpEF has a different pathology to that of systolic dysfunction. In this review, general concepts, epidemiology, diagnosis, and treatment of diastolic dysfunction are summarized, with an emphasis on new experiments suggesting that oxidative stress plays a crucial role in the pathogenesis of at least some forms of the disease. This observation has lead to potential new diagnostics and therapeutics for diastolic dysfunction and heart failure caused by diastolic dysfunction. PMID:25746522

Significant placental insufficiency, indicated by Doppler ultrasound findings of absent or reverse end-diastolic flow velocities (AREDV), is associated with increased morbidity and mortality. Analysis of blood flow in the ductus venosus should assist in early intrauterine recognition of threatened foetuses. 58 high-risk pregnancies with umbilical AREDV were repeatedly examined (n=364). Doppler findings were correlated with neonatal signs of deterioration (ratio of normoblasts to leukocytes, pH, base excess, Apgar score), as well as short-term morbidity [need for intubation, duration of assisted respiration, evidence of respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), necrotising enterocolitis (NEC), intraventricular haemorrhage (IVH grade III+IV)] against the analysis of the blood flow findings (normal or increased pulsitility, absence or reverse end-diastolic flow) in the umbilical arteries (AU), the middle cerebral arteries (ACM) and ductus venosus (DV) relating these to birth weight and the duration of the pregnancy. The median period of observation was 12.8 days, 48% of the foetuses showed an abnormal ductus venosus flow and 26% an absent venous or reverse end-diastolic flow. The median date of delivery was 30 weeks, with a mean birth weight of 816?g. 93% were live births with 12% dying postnatally. Although the criteria for postnatal morbidity (BPD, NEC, IVH III+IV) and mortality did not correlate with changes in arterial and venous Doppler parameters in our group, there was a significant relationship between the normoblast count, known to be a marker of chronic hypoxia. The Apgar 10?minte score, umbilical arterial pH and base excess were correlated with changes in the DV flow curves. Healthy survival started, irrespective of arterial or venous blood flow criteria, from 27+0 weeks of pregnancy. If born between 27.0 and 30+6 weeks, the infants were more likely to be healthy the less the blood flow had been compromised. A birth weight of 590?g (sensitivity 62.5%; specificity 93.5%) and gestational age of 28+5 weeks (sensitivity 87.5%; specificity 90.3%) were shown to be cut-off points between healthy survival and survival with serious neonatal complications. PMID:25734475

Full Text Available AIM: Whereas the prevalance of arterial blood pressure which was a chronical health problem was 20%-25% among 30 year-old people, them showing an increase in aging, the percentage went as high as 50% in 60?s and later ages. What was that worrisome was that despite the high prevalance, only half of these received treathment. This is study was descriptively and cross-sectionally planned to determine whether the people asking their tensions to be measured in and around the Yesilyurt local healthcare office region. METHODS: The environment of the research consisted of 1400 people over 35 age and registered Yesilyurt Local healthcare Office and the whole of the environment were included in this sample. The study was conducted over 340 voluntaries. The data was collected by a questionnaire of 14 questions containing socio-demografic features and by measuring the arterial blood pressure, height and weight of the individuals. In the evaluation of the data, chi-square test was used and the level of significantly was accepted as 0.05. RESULTS: In this study, the rate of high sistolic blood pressure was found to be 21.47% and the rate of high diastolic blood pressure to be 8.23%. It was determined that age and body mass index varrieties were effective on sistolic hipertension. It was also found that in their behaviors of the use of hypertensive medicine, of regular arterialpressure controls and of having the hypertesion diagnosis significant differnces varied statistically on both sistolic and diastolic blood pressure people having. CONCLUSION: In order to improve the health, informative information abouth hypertension was provided for the participants for too days consisting of 4 sessions. [TAF Prev Med Bull 2009; 8(1.000: 53-58

Full Text Available Introduction. An altered perfusion of the optic nerve head has been proposed as a pathogenic factor of glaucoma. Objective. The aim of this study was to evaluate the changes of the hemodynamic parameters in the retrobulbar arterial circulation after decrease of the elevated intraocular pressure (IOP in women and men with primary open angle glaucoma. Methods. The study included 60 patients (33 males and 27 females older than 50 years, with diagnosed and treated primary open angle glaucoma (77 eyes of 39 patients had increased IOP, >25 mm Hg. They were examined at the Clinic of Eye Diseases (complete ophthalmologic exam and Clinic of Neurology, Clinical Center of Serbia, Belgrade, from December 2009 to December 2010. Imaging of hemodynamic parameters of three retrobulbar arterial vessels: ophthalmic, central retinal and posterior ciliary arteries with color Doppler was performed. Results. Among women, hemodynamic arterial parameter of the peak-systolic velocity was increased in the central retinal artery and decreased in the ophthalmic artery and posterior ciliary arteries; end- diastolic velocity was increased in all three retrobulbar vascular levels; Pourcelot resistivity index was increased, but pulsatility index was decreased in all three vessels. Among men, peak-systolic velocity, end-diastolic velocity and pulsatility index were decreased in all three vessels; resistivity index was increased in the ophthalmic artery, but decreased in the central retinal artery and posterior ciliary arteries. There was a significant change of the ophthalmic artery pulsatility index in women, and the end-diastolic velocity of the ophthalmic artery in men. Conclusion. There was a difference of the retrobulbar arterial circulation between women and men with primary open angle glaucoma after decrease of the elevated intraocular pressure. The role of vascular factors in the supply of the optic disc neuroretinal rim is important.

White matter hyperintensities (WMH) are associated with hypertension. We examined interactions among blood pressure (BP), internal carotid artery (ICA) flow velocity parameters, and WMH. We obtained BP measurements from 694 community-dwelling subjects at mean ages 69.6 (±0.8) years and again at 72.6 (±0.7) years, plus brain MRI and ICA ultrasound at age 73±1 years. Diastolic and mean BP decreased and pulse pressure increased, but systolic BP did not change between 70 and 73 years. Multiple linear regression, corrected for vascular disease and risk factors, showed that WMH at the age of 73 years were associated with history of hypertension (?=0.13; Ptesting. Therefore, falling diastolic BP and increased pulse pressure are associated with increased ICA pulsatility index, which in turn is associated with WMH. This suggests that hypertension and WMH may either associate indirectly because hypertension increases arterial stiffness that leads to WMH over time, or coassociate through advancing age and stiffer vessels, or both. Reducing vascular stiffness may reduce WMH progression and should be tested in randomized trials, in addition to testing antihypertensive therapy. PMID:24470459

Full Text Available The purpose of the study is to find out the Effect of yoga therapy on selected Systolic Pressure and Diastolicpressure variables on stage one hyper tension Patients among men. Forty male subjects were selected randomly only hyper tension Patients among men at Indira Gandhi Medical College & Research Institute Hospital in Pondicherry. The subject’s age ranged from 40 to 45 years of respectively. The selected subjects were divided into two equal groups of 20 subjects each. Experimental group (Group I Yoga therapy and Control group (Group II. Pre-test was conducted for the two groups on selected Systolic Pressure and Diastolicpressure variables. The experimental group underwent Yoga therapy practices for 6 weeks, per week for the duration of the training was given for 5 days per week 45 minutes every day. The control group did not undergo any training program. After 6 weeks of training period the post test was conducted for all the two groups. The data was analyzed by applying Analysis of Variance (ANOVA Technique to find out the effect of yoga therapy on selected physiological variables on stage one hyper tension patients among men. Then, the obtained ‘f’ratio is tested at 0.05 level of significant

Full Text Available Aim: To analyze the effects of aircraft noise, resting pulse rate, and other factors on the risk of high diastolic blood pressure (DBP in Indonesian Air Force pilots.Methods: A nested case-control study was conducted using data extracted from annual medical check-ups indoctrination aerophysiologic training records at the Saryanto Aviation and Aerospace Health Institute (LAKESPRA in Jakarta from January 2003 – September 2008. For analysis of DBP: the case group with DBP ? 90 mmHg were compared with contral group with DBP < 79 mmHG. One case matched to 12 controls.Results: Out of 567 pilots, 544 (95.9% had complete medical records. For this analysis there were 40 cases of high DBP and 480 controls for DBP. Pilots exposed to aircraft noise 90-95 dB rather than 70-80 dB had a 2.7-fold increase for high DBP [adjusted odds ratio (ORa = 2.70; 95% confi dence interval (CI = 1.05-6.97]. Pilots with resting pulse rates of ? 81/minute rather than ? 80/minute had a 2.7-fold increase for high DBP (ORa = 2.66; 95% CI = 1.26-5.61. In terms of total fl ight hours, pilots who had 1401-11125 hours rather than 147-1400 hours had a 3.2-fold increase for high DBP (ORa = 3.18; 95% CI = 1.01-10.03.Conclusion: High interior aircraft noise, high total flight hours, and high resting pulse rate, increased risk for high DBP. Self assessment of resting pulse rate can be used to control the risk of high DBP. (Med J Indones 2009; 276: 276-82Keywords: diastolic blood pressure, aircraft noise, resting pulse rate, military pilots

Although the phenotypic correlation between systolic blood pressure (SBP) and diastolic blood pressure (DBP) is well known, the genetic basis for the correlation has rarely been investigated. The aim of this paper is to examine the genetic overlap between SBP and DBP by fitting bivariate models to Danish and Chinese twins and comparing ethnic differences between the two samples. Our estimates revealed a high proportion of additive genetic components shared by both SBP and DBP in Danish (0.71, 95% confidence interval (CI): 0.65-0.75) and Chinese (0.62, 95% CI: 0.50-0.71) twins with no statistically significant ethnic differences. The estimated genetic component in phenotypic correlation could serve to guide molecular genetic studies searching for genetic variants that affect both SBP and DBP. The bivariate model also estimated genetic and environmental contributions to SBP and DBP separately, with an overall pattern of higher genetic regulation or heritability in Danish (0.72, 95% CI: 0.67-0.76 for SBP; 0.70, 95% CI: 0.65-0.75 for DBP) than in Chinese (0.54, 95% CI: 0.44-0.63 for SBP; 0.57, 95% CI: 0.47-0.65 for DBP) twins and a higher contribution from unique environmental factors in Chinese compared with Danish twins. The estimated contribution from unique environmental factors suggests that promoting healthy lifestyles may provide an efficient way of controlling high blood pressure, particularly in the Chinese population.

Full Text Available Objectives: The relationship between obesity and essential hypertension is well known. In this study, we aimed to evaluate ambulatory arterial blood pressure monitoring of obese and non-obese children who had similar demographic characteristics.Materials and methods: Seventy one children and adolescents (n=39 obesity, n=32 controls were studied. Blood pressure of the children were measured by 24 hour ambulatory blood pressure monitoring device.Results: Obese children had significantly higher mean blood pressure values (systolic 121.9±11.7 mmHg, diastolic 70.2±5.3 mmHg than control subjects (systolic 109.3±6.7 mmHg, diastolic 65.1±4.6 mmHg, p0.05. Blood pressure load was found to be increased in obese children compared to the controls (%13.6±12.9 and %2.6±3.4, respectively; p<0.05. Serum total cholesterol and LDL-cholesterol levels of obese children (181.1±33.4 and 131.1±23.1mg/dl were significantly higher than those of the controls (134.3±11.1 and 103.3±14.2 mg/dl, p<0.05.Conclusions: Obesity in children and adolescents should not be regarded as variations of normality, but as abnormality with an extremely high risk for the development of hypertension and hyperlipidemia in adulthood.

Full Text Available The available data suggests that hypotension caused by Hg2+ administration may be produced by a reduction of cardiac contractility or by cholinergic mechanisms. The hemodynamic effects of an intravenous injection of HgCl2 (5 mg/kg were studied in anesthetized rats (N = 12 by monitoring left and right ventricular (LV and RV systolic and diastolicpressures for 120 min. After HgCl2 administration the LV systolic pressure decreased only after 40 min (99 ± 3.3 to 85 ± 8.8 mmHg at 80 min. However, RV systolic pressure increased, initially slowly but faster after 30 min (25 ± 1.8 to 42 ± 1.6 mmHg at 80 min. Both right and left diastolicpressures increased after HgCl2 treatment, suggesting the development of diastolic ventricular dysfunction. Since HgCl2 could be increasing pulmonary vascular resistance, isolated lungs (N = 10 were perfused for 80 min with Krebs solution (continuous flow of 10 ml/min containing or not 5 µM HgCl2. A continuous increase in pulmonary vascular resistance was observed, suggesting the direct effect of Hg2+ on the pulmonary vessels (12 ± 0.4 to 29 ± 3.2 mmHg at 30 min. To examine the interactions of Hg2+ and changes in cholinergic activity we analyzed the effects of acetylcholine (Ach on mean arterial blood pressure (ABP in anesthetized rats (N = 9 before and after Hg2+ treatment (5 mg/kg. Using the same amount and route used to study the hemodynamic effects we also examined the effects of Hg2+ administration on heart and plasma cholinesterase activity (N = 10. The in vivo hypotensive response to Ach (0.035 to 10.5 µg was reduced after Hg2+ treatment. Cholinesterase activity (µM h-1 mg protein-1 increased in heart and plasma (32 and 65%, respectively after Hg2+ treatment. In conclusion, the reduction in ABP produced by Hg2+ is not dependent on a putative increase in cholinergic activity. HgCl2 mainly affects cardiac function. The increased pulmonary vascular resistance and cardiac failure due to diastolic dysfunction of both ventricles are factors that might contribute to the reduction of cardiac output and the fall in arterialpressure.

Full Text Available The available data suggests that hypotension caused by Hg2+ administration may be produced by a reduction of cardiac contractility or by cholinergic mechanisms. The hemodynamic effects of an intravenous injection of HgCl2 (5 mg/kg) were studied in anesthetized rats (N = 12) by monitoring left and ri [...] ght ventricular (LV and RV) systolic and diastolicpressures for 120 min. After HgCl2 administration the LV systolic pressure decreased only after 40 min (99 ± 3.3 to 85 ± 8.8 mmHg at 80 min). However, RV systolic pressure increased, initially slowly but faster after 30 min (25 ± 1.8 to 42 ± 1.6 mmHg at 80 min). Both right and left diastolicpressures increased after HgCl2 treatment, suggesting the development of diastolic ventricular dysfunction. Since HgCl2 could be increasing pulmonary vascular resistance, isolated lungs (N = 10) were perfused for 80 min with Krebs solution (continuous flow of 10 ml/min) containing or not 5 µM HgCl2. A continuous increase in pulmonary vascular resistance was observed, suggesting the direct effect of Hg2+ on the pulmonary vessels (12 ± 0.4 to 29 ± 3.2 mmHg at 30 min). To examine the interactions of Hg2+ and changes in cholinergic activity we analyzed the effects of acetylcholine (Ach) on mean arterial blood pressure (ABP) in anesthetized rats (N = 9) before and after Hg2+ treatment (5 mg/kg). Using the same amount and route used to study the hemodynamic effects we also examined the effects of Hg2+ administration on heart and plasma cholinesterase activity (N = 10). The in vivo hypotensive response to Ach (0.035 to 10.5 µg) was reduced after Hg2+ treatment. Cholinesterase activity (µM h-1 mg protein-1) increased in heart and plasma (32 and 65%, respectively) after Hg2+ treatment. In conclusion, the reduction in ABP produced by Hg2+ is not dependent on a putative increase in cholinergic activity. HgCl2 mainly affects cardiac function. The increased pulmonary vascular resistance and cardiac failure due to diastolic dysfunction of both ventricles are factors that might contribute to the reduction of cardiac output and the fall in arterialpressure.

The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10?8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10?8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10?6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10?6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexity. PMID:21378095

Purpose: The purpose of this work was to evaluate blood pressure changes caused by deployment of the Surefire antireflux expandable tip. The pressure measurements are relevant because they imply changes in hepatoenteric arterial blood flow within this liver compartment during hepatic artery delivery of cytotoxic agents. Methods: After positioning the Surefire antireflux system in the targeted hepatic artery, blood pressure was obtained initially with the tip collapsed (or through a femoral artery sheath), then again after the tip was expanded before chemoembolization or yttrium 90 (90Y) radioembolization. Results: Eighteen patients with liver malignancy underwent 29 procedures in 29 hepatic arteries (3 common hepatic, 22 lobar, 4 segmental). Systolic, diastolic, and mean blood pressure were all decreased by a mean of 29 mm Hg (p = 0.000004), 14 mm Hg (p = 0.0000004), and 22 mm Hg (p = 0.00000001), respectively. Conclusion: When the Surefire expandable tip is deployed to prevent retrograde reflux of agents, it also results in a significant decrease in blood pressure in the antegrade distribution, potentially resulting in hepatopedal blood flow in vessels that are difficult to embolize, such as the supraduodenal arteries

Full Text Available PURPOSE: To assess the effects of the elevation of the left ventricular end-diastolicpressure (LVEDP on the value of the 1st temporal derivative of the ventricular pressure (dP/dt. METHODS: Nineteen anesthetized dogs were studied. The dogs were mechanically ventilated and underwent thoracotomy with parasympathetic nervous system block. The LVEDP was controlled with the use of a perfusion circuit connected to the left atrium and adjusted to the height of a reservoir. The elevation of the LVEDP was achieved by a sudden increase in the height of a reservoir filled with blood. Continuous recordings of the electrocardiogram, the aortic and ventricular pressures and the dP/dt were performed. RESULTS: Elevation of the LVEDP did not result in any variation of the heart rate (167±16.0bpm, before the procedure; 167±15.5bpm, after the procedure. All the other variables assessed, including systolic blood pressure (128±18.3mmHg and 150±21.5mmHg, diastolic blood pressure (98±16.9mmHg and 115±19.8mmHg, LVEDP (5.5±2.49 and 9.3±3.60mmHg, and dP/dt (4,855 ± 1,082 mmHg/s and 5,149±1,242mmHg/s showed significant increases following the expansion of the ventricular cavity. Although the elevation of the dP/dt was statistically significant, 6 dogs curiously showed a decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP resulted in increased values of dP/dt; however, in some dogs, this response was not uniform.

Full Text Available PURPOSE: To assess the effects of the elevation of the left ventricular end-diastolicpressure (LVEDP) on the value of the 1st temporal derivative of the ventricular pressure (dP/dt). METHODS: Nineteen anesthetized dogs were studied. The dogs were mechanically ventilated and underwent thoracotomy wi [...] th parasympathetic nervous system block. The LVEDP was controlled with the use of a perfusion circuit connected to the left atrium and adjusted to the height of a reservoir. The elevation of the LVEDP was achieved by a sudden increase in the height of a reservoir filled with blood. Continuous recordings of the electrocardiogram, the aortic and ventricular pressures and the dP/dt were performed. RESULTS: Elevation of the LVEDP did not result in any variation of the heart rate (167±16.0bpm, before the procedure; 167±15.5bpm, after the procedure). All the other variables assessed, including systolic blood pressure (128±18.3mmHg and 150±21.5mmHg), diastolic blood pressure (98±16.9mmHg and 115±19.8mmHg), LVEDP (5.5±2.49 and 9.3±3.60mmHg), and dP/dt (4,855 ± 1,082 mmHg/s and 5,149±1,242mmHg/s) showed significant increases following the expansion of the ventricular cavity. Although the elevation of the dP/dt was statistically significant, 6 dogs curiously showed a decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP resulted in increased values of dP/dt; however, in some dogs, this response was not uniform.

Occupational exposure to lead may cause an increase in blood pressure. The aim of the study was to estimate the effect of occupational exposure to lead on selected parameters of ambulatory blood pressure monitoring (ABPM) and structural changes in carotid arteries. The study included 33 normotensive men occupationally exposed to lead and 39 unexposed men employed in administration of the foundry. All of the men underwent 24-hour ambulatory blood pressure monitoring and high-resolution B-mode ultrasonography to determine intima-media thickness (IMT). The group of men occupationally exposed to lead manifested significantly higher mean systolic blood pressure (MSBP), mean diastolic blood pressure (MDBP), mean blood pressure (MBP), pulse pressure (PP), variability of diastolic blood pressure (VDBP), and IMT than the unexposed group. The studied groups did not differ in mean values of variability of systolic blood pressure (VSBP). As compared to the unexposed group, in men exposed to lead, atherosclerotic plaques were significantly more common. In the group of persons exposed to lead the Pearson's correlation coefficient analysis revealed significant linear positive correlations between MSBP and IMT, between lead level and the number of atherosclerotic plaques, and between lead level and PP. Multivariate stepwise regression analysis demonstrated that higher lead level in blood and higher triglyceride concentration in blood represent independent risk factors of an increased pulse pressure in the group of individuals occupationally exposed to lead. Occupational exposure to lead can be associated with increased blood pressure and accelerated progression of atherosclerosis. PMID:21148199

Full Text Available Abstract Background About one quarter of adults are hypertensive and high blood pressure carries increased risk for heart disease, stroke, kidney disease and death. Increased arterial stiffness is a key factor in the pathogenesis of systolic hypertension and cardiovascular disease. Substantial heritability of blood-pressure (BP and arterial-stiffness suggests important genetic contributions. Methods In Framingham Heart Study families, we analyzed genome-wide SNP (Affymetrix 100K GeneChip associations with systolic (SBP and diastolic (DBP BP at a single examination in 1971–1975 (n = 1260, at a recent examination in 1998–2001 (n = 1233, and long-term averaged SBP and DBP from 1971–2001 (n = 1327, mean age 52 years, 54% women and with arterial stiffness measured by arterial tonometry (carotid-femoral and carotid-brachial pulse wave velocity, forward and reflected pressure wave amplitude, and mean arterialpressure; 1998–2001, n = 644. In primary analyses we used generalized estimating equations in models for an additive genetic effect to test associations between SNPs and phenotypes of interest using multivariable-adjusted residuals. A total of 70,987 autosomal SNPs with minor allele frequency ? 0.10, genotype call rate ? 0.80, and Hardy-Weinberg equilibrium p ? 0.001 were analyzed. We also tested for association of 69 SNPs in six renin-angiotensin-aldosterone pathway genes with BP and arterial stiffness phenotypes as part of a candidate gene search. Results In the primary analyses, none of the associations attained genome-wide significance. For the six BP phenotypes, seven SNPs yielded p values -5. The lowest p-values for SBP and DBP respectively were rs10493340 (p = 1.7 × 10-6 and rs1963982 (p = 3.3 × 10-6. For the five tonometry phenotypes, five SNPs had p values -5; lowest p-values were for reflected wave (rs6063312, p = 2.1 × 10-6 and carotid-brachial pulse wave velocity (rs770189, p = 2.5 × 10-6 in MEF2C, a regulator of cardiac morphogenesis. We found only weak association of SNPs in the renin-angiotensin-aldosterone pathway with BP or arterial stiffness. Conclusion These results of genome-wide association testing for blood pressure and arterial stiffness phenotypes in an unselected community-based sample of adults may aid in the identification of the genetic basis of hypertension and arterial disease, help identify high risk individuals, and guide novel therapies for hypertension. Additional studies are needed to replicate any associations identified in these analyses.

Background and Purpose Elevated blood pressure (BP) is a risk factor for stroke and dementia, but the effect of BP, and change in BP over time, on WMHV is not fully understood. Few studies have included Hispanics, who are at greater risk of stroke and dementia than non-Hispanic whites. We examined BP in relation to white matter hyperintensity volume (WMHV) in a stroke-free cohort. Methods The Northern Manhattan Study includes 1,290 stroke-free participants who had brain MRI. We examined baseline systolic (SBP) and diastolic (DBP) BP, and changes in BP from baseline to MRI, and WMHV. Results There were 1,281 participants with brain MRI and two BP measurements (mean age 64, SD=8, range 40–94). Baseline DBP was associated with greater WMHV (p5 mm Hg DBP from baseline to MRI had 1.21% greater WMHV relative to those whose BP did not increase (p = 0.02). The association between baseline DBP and WMHV was strongest for blacks compared to Hispanics and whites (interaction p=0.04). Conclusions Baseline DBP and longitudinal increases in DBP were independently associated with a greater WMHV, and the association between DBP and WMHV was greatest among blacks. PMID:21836088

Full Text Available Abstract Background Overt hypothyroidism has been associated with arterial hypertension and increased arterial stiffness. Results in euthyroid individuals have been conflicting. We investigated associations of thyroid function with systolic (SAP and diastolic (DAP arterialpressure in euthyroid subjects. Methods 311 euthyroid individuals (185 women, mean age 43.9 ± 9 without a history of diabetes attending a preventive medicine program were examined. Subjects receiving thyroxine (10.6% were excluded; 19.3% had hypertension, 43% had a family history for hypertension. TSH, fT4, thyroid autoantibodies, insulin, glucose were measured. The "fT4.TSH product", which has been suggested as a T4 resistance-index, was calculated. Results TSH range was 0.1–8, median 1.4 mU/L, fT4 range was 11.5–25.2 pmol/L, median 17.4. TSH and the "fT4.TSH product" were positively associated with DAP (p 2 mU/L (35.3% vs 21.3%, p = 0.045. Conclusion In euthyroid individuals the association of thyroid function with diastolicarterialpressure remains significant even when a stricter "normal range" for TSH levels is considered. The "freeT4.TSH" product appears to be an even stronger predictor of DAP, independently of HOMA insulin resistance index and obesity.

Hypertension is strongly associated with cardio/cerebrovascular diseases, e.g. myocardial infarction, stroke, and heart failure, which are main causes of cardiovascular morbidity and mortality. In hypertensive subjects, cardiovascular risk reduction is mainly associated with reduction in brachial systolic blood pressure (SBP). As it was shown in controlled and long-term therapeutic trials, it is possible to produce a selective SBP reduction through a specific "de-stiffening" strategy. This means that SBP reduction is obtained independently of mean arterialpressure change, using a significant and selective reduction of wave reflections and/or aortic stiffness. The procedure is especially effective in decreasing central systolic and pulse pressures, which were shown to be major determinants of long-term outcome. As some concerns associated with decreasing in diastolic blood pressure to low values (so called "J-curve" phenomenon) have been raised recently the de-stiffening strategy appears to be especially attractive. Most of the protocols used to de-stiffen large arteries required the administration of a renin-angiotensin-aldosterone system inhibitor, which frequently was associated with a diuretic and/or a calcium antagonist, but not with a classic beta-blocker. These protocols were evaluated in randomized controlled trials and showed significant reduction in cardiovascular risk, particularly in comparison with beta-blockers. PMID:21621778

The present study aimed at an investigation of the relation between arterial blood pressure and cardiac filling in patients with severe postural hypotension. Seven patients aged 49 to 84 years were studied during head-up tilt at three different tilt angles (median values: 0, 25, and 45 degrees) using intraarterial blood pressure recordings and estimates of left ventricular volumes by radioisotope ventriculography. Mean arterial blood pressure was reduced from 105 mmHg (79-129) in the horizontal position to 97 mmHg (61-112) and 83 mmHg (36-93; p < 0.0001), respectively, in parallel with a reduction in left ventricular end-diastolic volume index from 59 ml m-2 (30-65) to 36 ml m-2 (23-44) and 22 ml m-2 (16-38; p < 0.001). Left ventricular contractility was high, and the postural reductions in cardiac output were unopposed by vasoconstriction. The study has demonstrated that blood pressure is strongly dependent upon cardiac filling in severe postural hypotension, and has underlined the importance of intravascular volume expansion as a measure against postural hypotension. PMID:7846778

Full Text Available There is an urgent need to treat individuals with high blood pressure (BP with effective dietary strategies. Previous studies suggest a small, but significant decrease in BP after lactotripeptides (LTP ingestion, although the data are inconsistent. The study aim was to perform a comprehensive meta-analysis of data from all relevant randomised controlled trials (RCT. Medline, Cochrane library, EMBASE and Web of Science were searched until May 2014. Eligibility criteria were RCT that examined the effects of LTP on BP in adults, with systolic BP (SBP and diastolic BP (DBP as outcome measures. Thirty RCT met the inclusion criteria, which resulted in 33 sets of data. The pooled treatment effect for SBP was ?2.95 mmHg (95% CI: ?4.17, ?1.73; p < 0.001, and for DBP was ?1.51 mmHg (95% CI: ?2.21, ?0.80; p < 0.001. Sub-group analyses revealed that reduction of BP in Japanese studies was significantly greater, compared with European studies (p = 0.002 for SBP and p < 0.001 for DBP. The 24-h ambulatory BP (AMBP response to LTP supplementation was statistically non-significant (p = 0.101 for SBP and p = 0.166 for DBP. Both publication bias and “small-study effect” were identified, which shifted the treatment effect towards less significant SBP and non-significant DBP reduction after LTP consumption. LTP may be effective in BP reduction, especially in Japanese individuals; however sub-group, meta-regression analyses and statistically significant publication biases suggest inconsistencies.

Blood pressure (BP) variability is generally considered to be due to neurogenic influences on arterioles modulating peripheral resistance, as well as variations in stroke volume (SV). However, for a given change in peripheral resistance or SV, the degree of BP variability is modulated by the stiffness of large conduit arteries. Recent epidemiological evidence shows that cardiovascular risk is not only related to the average arterialpressure, but also to the degree of diurnal variability. In addition, short-term variability has been shown to be related to aortic stiffness measured as pulse wave velocity, a strong independent predictor of cardiovascular risk. This study addresses the relation between large artery stiffness and BP variability using a lumped parameter model of the systemic circulation described by total arterial compliance, total peripheral resistance (TPR) and aortic characteristic impedance. The variability in TPR is simulated using a random function with a Gaussian distribution and changes in arterial stiffness are simulated by variation in compliance, where compliance is either linear (pressure independent) or nonlinear (pressure dependent). Simulation results show that (i) BP variability is greater when due to changes in TPR compared to similar relative changes in SV, (ii) pressure dependency of arterial stiffness results in a curvilinear relation between systolic BP variability and mean arterialpressure (MAP), such that a critical mean pressure (MAPc) exists for minimal BP variability, (iii) increase in arterial stiffness (as occurs with aging) result in a higher MAPc for minimal BP variability, or increased BP variability at older age for similar values of MAP. These findings suggest that interventions aimed at reducing BP variability will need to consider large artery stiffness for optimal efficacy. PMID:24110628

Full Text Available Persistent non-valvular atrial fibrillation (NVAF is associated with an increased risk of cardiovascular events such as stroke, and its rate is expected to rise because of the ageing population. The absolute rate of stroke depends on age and comorbidity. Risk stratification for stroke in patients with NVAF derives from populations enrolled in randomized clinical trials. However, participants in clinical trials are often not representative of the general population. Many stroke risk stratification scores have been used, but they do not include transthoracic echocardiogram (TTE, pulsate wave Doppler (PWD and tissue Doppler imaging (TDI, simple and non-invasive diagnostic tools. The role of TTE, PWD and TDI findings has not been previously determined. Our study goal was to determine the association between TTE and PWD findings and stroke prevalence in a population of NVAF prone outpatients. Patients were divided into two groups: P for stroke prone and F for stroke free. There were no statistically significant differences between the two groups concerning cardiovascular risk factors, age (p=0.2, sex (p=0.2, smoking (p=0.3, diabetes (p=0.1 and hypercholesterolemia (p=0.2; hypertension was statistically significant (p less than 0.001. There were statistically significant differences concerning coronary artery disease, previous acute myocardial infarction (AMI (p less than 0.05 and non- AMI coronaropathy (p less than 0.04, a higher rate being in the P group. Concerning echo-Doppler findings, a higher statistically significant rate of left ventricular hypertrophy (LVH (pless than 0.05 and left ventricular diastolic dysfunction (pless than 0.001 was found in the P group and dilated left atrium (pless than 0.04 in the F group, the difference was not significant for mitral regurgitation (p=0.7. Stroke prone NVAF patients have a higher rate of hypertension, coronary artery disease, with and without AMI, LVH and left ventricular diastolic dysfunction, but not left atrial dilatation. M-B mode echocardiography and PWD examination help to identify high-risk stroke patients among NVAF subjects; therefore, they may help in the selection of appropriate therapy for each patient.

The arterial blood pressure values and the evolutive pattern of a normal middle class children population of both sexes between 4 to 18 years of age are reported. The findings are discussed. PMID:7426136

Arterial blood pressure circadian rhythm: significance and clinical implications Arterial blood pressure exhibits a circadian rhythm characterized by a decrease during the sleep period and a steep increase in the early morning hours that can be characterized by 24 h ambulatory blood pressure monitoring (ABPM). The absence of a nocturnal dipping or an excessive morning surge, commonly observed in hypertensive patients, is associated with an increased cardiovascular and renal risk. Numerous studies show that a better control of nocturnal blood pressure can be obtained by the administration of anti-hypertensive medication at the evening time, improving microalbuminuria, left heart hypertrophy, or arterial intima-media thickness, but only one study has so far demonstrated a decrease of major cardiovascular events. In this context, the decision on restoring or not the nocturnal dipping should be left to the judgement of the clinician, and applied in an individual manner to each patient. PMID:23029984

Diastolic dysfunction is a prognosticator for future cardiovascular events that demonstrates a strong correlation with obesity. Pharmacological inhibition of dipeptidylpeptidase-4 (DPP-4) to increase the bioavailability of glucagon-like peptide-1 is an emerging therapy for control of glycemia in type 2 diabetes patients. Accumulating evidence suggests that glucagon-like peptide-1 has insulin-independent actions in cardiovascular tissue. However, it is not known whether DPP-4 inhibition improv...

Full Text Available This paper presents an implantable system for telemonitoring the intravascular pressure in the pulmonary artery. By implanting a catheter-bound pressure and temperature sensor into the pulmonary artery, it is possible to monitor the actual value and the time variations of the intravascular pressure with a frequency of 128 Hz. Thus hospitalization of patients suffering from heart insufficiency can be avoided by early changes in therapy.Preliminary in vivo experiments have been conducted to verify the fixation mechanism and the positioning of the sensor at the right place in the pulmonary artery. It was shown that the proposed fixation mechanism and the packaging of the sensor promise to be stable.

Full Text Available GeeHee Kim,1 Ji-Hoon Kim,1 Keon-Woong Moon,1 Ki-Dong Yoo,1 Sang-Hyun Ihm,2 Ho-Joong Youn,2 Chul-Min Kim11Division of Cardiology, Department of Internal Medicine, St Vincent's Hospital, Catholic University of Korea, Suwon, 2Division of Cardiology, Department of Internal Medicine, School of Medicine, Catholic University of Korea, Seoul, South KoreaObjective: Diastolic dysfunction is associated with increased arterial stiffness in patients with hypertension. However, the role of arterial stiffness in diastolic dysfunction in subjects without hypertension has not been fully established.Materials and methods: A total of 287 subjects (male:female ratio 121:166, mean age 53.0±14.4 years without hypertension or any heart disease who simultaneously received transthoracic echocardiography and noninvasively semiautomated radial artery applanation tonometry (with an Omron HEM-9000AI in the Department of Internal Medicine, St Vincent’s Hospital, from July 2011 to September 2012, were enrolled in this study.Results: A total of 147 subjects (male:female ratio 59:88, mean age 61.7±9.9 years, representing 51.2% of the 287 subjects, had diastolic dysfunction (defined as abnormal relaxation pattern of mitral inflow. There were significant differences in systolic blood pressure (BP, pulse pressure, late systolic peak pressure (SBP2, and radial augmentation index (RaAIx between normal diastolic function and diastolic dysfunction. ?BP was defined as systolic BP minus SBP2, because of the difference in systolic BP between the two groups. ?BP (odds ratio [OR] 1.059, 95% confidence interval [CI] 1.005–1.115; P=0.032 and RaAIx (odds ratio 1.027, 95% CI 1.009–1.044, P=0.003 were associated with diastolic dysfunction. A receiver operating-characteristic curve showed that ?BP (area under the curve 0.875, 95% CI 0.832–0.911 and RaAIx (area under the curve 0.878, 95% CI 0.835–0.914 were associated with diastolic dysfunction.Conclusion: We found that ?BP and increased RaAIx were associated with diastolic dysfunction in subjects without hypertension after adjustment for age and sex. Therefore, it is suggested that noninvasive estimation of central BP may be useful to reflect diastolic dysfunction in subjects with normal peripheral BP.Keywords: central blood pressure, augmentation index, diastolic dysfunction

Polycystic kidney disease (PKD) in Persian cats has been increasingly reported and compared to human autosomal dominant polycystic kidney disease (ADPKD) in the last decade. In cats, however, few studies have dealt with the occurrence and hormonal determinants of hypertension, one of the most common extrarenal manifestations of ADPKD in humans. The purpose of this study was to compare Persian cats >4 years old with PKD to unaffected control cats with regard to blood pressure (BP), plasma renin activity (PRA), serum aldosterone concentration, plasma atrial natriuretic peptide (ANP) concentration, and aldosterone-to-renin ratio (ARR). Three gender- and age-matched groups were studied, each consisting of 7 cats: (1) a control group without cysts, (2) a group with mild PKD, and (3) a group with severe PKD (multiple cysts and renal enlargement). Mild renal insufficiency was found in only 1 of 14 cats with PKD. Cats with PKD had a higher mean arterialpressure (P = .04) and more often had a high ARR (P = .047) than did control cats. Tendencies toward higher diastolic and systolic arterialpressures (DAPs and SAPs, respectively) and lower PRAs were observed in cats with PKD compared to controls (.05 cats had echocardiographic evidence of cardiac hypertrophy. In conclusion, cats with PKD had a minor increase in mean arterialpressure compared to control cats, and half of the cats had a high ARR. PMID:12564723

Differences between central aortic root (c) and peripheral (p) systolic blood pressure (SBP) may be particularly marked in children, but noninvasive methods for assessing cSBP in children have not been validated. We compared estimates of cSBP obtained from radiofrequency ultrasound wall tracking of the carotid artery (ART.LAB system) with that measured directly by a catheter in the aortic root at the time of arterial cannulation. Carotid waveforms were calibrated from invasive measurements of mean and diastolicpressures. In 9 children aged 10.5 ± 5.0 years (mean ± SD), cSBP obtained from carotid wall tracking was highly correlated with invasive measures of cSBP (r=0.99) with mean (± SD) difference 3.9 ± 2.5 mm?Hg. Second, we compared values of cSBP obtained from the carotid with those obtained using noninvasive applanation tonometry at the radial artery and a radial-to-aortic transfer function (SphygmoCor). Both carotid and radial tonometric measurements were calibrated from the same peripheral mean and diastolic measurements of blood pressure obtained by sphygmomanometry. In 84 children aged 13.2 ± 3.2 years, there was excellent agreement between the 2 methods (r=0.95; Pperipheral blood pressure measurements. PMID:25824246

Full Text Available Background and Aim: Recently, National Health and Nutritional Examination Survey-1 data analysis found short sleep duration as a risk factor for hypertension in the U.S. population. However, since ethnic differences exist in the aetiopathogenesis of diseases, the current study was undertaken to study the effect of sleep duration on the blood pressure profile of Gujarati Indian adolescents. Materials and Methods: A cross-sectional study was conducted on 489 Gujarati Indian adolescents of age group 16-19 years studying in school and colleges in the local population. The participants were assessed for their sleep duration, physical activity status, body composition, blood pressure profile and cardiovascular reactivity. The sleep duration was reported by the subjects as the number of hours they slept on most of the nights in a week over the last one year. The observations of the study were then analyzed after grouping them into: 1 Adequate Sleep Duration at Night, ASDN (? 7 hrs and 2 Inadequate Sleep Duration at Night, ISDN (< 7 hrs groups. Student?s unpaired t-test was used to study if any significant difference (P< 0.05 existed between the groups. Results: No significant difference was found in Systolic blood pressure, Diastolic blood pressure, Pulse pressure and Mean arterialpressure between the ASDN group and the ISDN group. Physical activity status also did not differ between the two groups. However, adolescents of ISDN group showed a significantly higher level of adiposity and cardiovascular reactivity as compared to adolescents of ASDN group. Conclusion: Although short sleep duration is associated with a higher level of adiposity and cardiovascular reactivity in Gujarati Indian adolescents, it does not affect the resting blood pressure profile of these adolescents. However, longitudinal studies would be required to observe if the changes in adiposity and cardiovascular reactivity affect these adolescents in later life.

BACKGROUND: Low plasma 25-hydroxyvitamin D (25[OH]D) concentration is associated with high arterial blood pressure and hypertension risk, but whether this association is causal is unknown. We used a mendelian randomisation approach to test whether 25(OH)D concentration is causally associated with blood pressure and hypertension risk. METHODS: In this mendelian randomisation study, we generated an allele score (25[OH]D synthesis score) based on variants of genes that affect 25(OH)D synthesis or substrate availability (CYP2R1 and DHCR7), which we used as a proxy for 25(OH)D concentration. We meta-analysed data for up to 108?173 individuals from 35 studies in the D-CarDia collaboration to investigate associations between the allele score and blood pressure measurements. We complemented these analyses with previously published summary statistics from the International Consortium on Blood Pressure (ICBP), the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and the Global Blood Pressure Genetics (Global BPGen) consortium. FINDINGS: In phenotypic analyses (up to n=49?363), increased 25(OH)D concentration was associated with decreased systolic blood pressure (? per 10% increase, -0·12 mm Hg, 95% CI -0·20 to -0·04; p=0·003) and reduced odds of hypertension (odds ratio [OR] 0·98, 95% CI 0·97-0·99; p=0·0003), but not with decreased diastolic blood pressure (? per 10% increase, -0·02 mm Hg, -0·08 to 0·03; p=0·37). In meta-analyses in which we combined data from D-CarDia and the ICBP (n=146?581, after exclusion of overlapping studies), each 25(OH)D-increasing allele of the synthesis score was associated with a change of -0·10 mm Hg in systolic blood pressure (-0·21 to -0·0001; p=0·0498) and a change of -0·08 mm Hg in diastolic blood pressure (-0·15 to -0·02; p=0·01). When D-CarDia and consortia data for hypertension were meta-analysed together (n=142?255), the synthesis score was associated with a reduced odds of hypertension (OR per allele, 0·98, 0·96-0·99; p=0·001). In instrumental variable analysis, each 10% increase in genetically instrumented 25(OH)D concentration was associated with a change of -0·29 mm Hg in diastolic blood pressure (-0·52 to -0·07; p=0·01), a change of -0·37 mm Hg in systolic blood pressure (-0·73 to 0·003; p=0·052), and an 8·1% decreased odds of hypertension (OR 0·92, 0·87-0·97; p=0·002). INTERPRETATION: Increased plasma concentrations of 25(OH)D might reduce the risk of hypertension. This finding warrants further investigation in an independent, similarly powered study. FUNDING: British Heart Foundation, UK Medical Research Council, and Academy of Finland.

Seventeen patients with coronary artery disease were studied with cineangiography and simultaneous tip manometry at resting heart rate and maximal tachycardia induced by atrial pacing. During early diastole, defined as the interval from the opening of the mitral valve to the point of minimal left ventricular pressure, 20 percent of total ventricular filling took place at resting heart rate, but 62 percent occurred during tachycardia. Minimal pressure was significantly correlated with the time...

Full Text Available OBJECTIVE: To compare sleepiness scores of the Epworth scale in patients with different levels of arterialpressure when undergoing outpatient monitoring within the context of clinical evaluation. METHODS: A total of 157 patients selected for outpatient monitoring of arterialpressure during hypertension evaluation were divided into 3 groups: group 1 - normotensive; group 2 - hypertensive; group 3 - resistant hypertensive. For analysis, values > or = 11 were considered as associated with respiratory disturbances during sleep. RESULTS: Seventeen (10.8% patients in group 1, 112 (71.3% in group 2, and 28 (17.8% in group 3, which was composed of aged, more severely hypertensive individuals, were analyzed. Groups were similar relative to sex and body mass index, but different in relation to systolic and diastolicpressure levels and age. Despite an absolute difference, no statistically significant difference occurred between Epworth scores and in the proportion of patients with values > or = 11 (5.9% vs. 18.8% vs. 212.4%; P=0.37. Despite the positive association between degree of sleepiness measured with the scale and the severity of the hypertension, no statistical significance occurred following control by age (p=0.18. CONCLUSION: A positive correlation exists between degree of sleepiness and hypertension severity. The absence of a statistical significance shown in the present study could be due to a beta type of error. Instruments that render this complaint into an objective finding could help in the pursuit of an investigation of respiratory disturbances during sleep in more severely hypertensive patients, and should therefore be studied better.

Full Text Available OBJECTIVE: To compare sleepiness scores of the Epworth scale in patients with different levels of arterialpressure when undergoing outpatient monitoring within the context of clinical evaluation. METHODS: A total of 157 patients selected for outpatient monitoring of arterialpressure during hyperte [...] nsion evaluation were divided into 3 groups: group 1 - normotensive; group 2 - hypertensive; group 3 - resistant hypertensive. For analysis, values > or = 11 were considered as associated with respiratory disturbances during sleep. RESULTS: Seventeen (10.8%) patients in group 1, 112 (71.3%) in group 2, and 28 (17.8%) in group 3, which was composed of aged, more severely hypertensive individuals, were analyzed. Groups were similar relative to sex and body mass index, but different in relation to systolic and diastolicpressure levels and age. Despite an absolute difference, no statistically significant difference occurred between Epworth scores and in the proportion of patients with values > or = 11 (5.9% vs. 18.8% vs. 212.4%; P=0.37). Despite the positive association between degree of sleepiness measured with the scale and the severity of the hypertension, no statistical significance occurred following control by age (p=0.18). CONCLUSION: A positive correlation exists between degree of sleepiness and hypertension severity. The absence of a statistical significance shown in the present study could be due to a beta type of error. Instruments that render this complaint into an objective finding could help in the pursuit of an investigation of respiratory disturbances during sleep in more severely hypertensive patients, and should therefore be studied better.

Full Text Available Laurent Lonjaret,1 Olivier Lairez,2 Vincent Minville,3 Thomas Geeraerts3 1Department of Anesthesiology and Intensive Care, Clinique des eaux claires, Baie-Mahault, France; 2Department of Cardiology, 3Department of Anesthesiology and Intensive Care, University Hospital of Toulouse, University Toulouse III - Paul Sabatier, Toulouse, France Abstract: Perioperative blood pressure management is a key factor of patient care for anesthetists, as perioperative hemodynamic instability is associated with cardiovascular complications. Hypertension is an independent predictive factor of cardiac adverse events in noncardiac surgery. Intraoperative hypotension is one of the most encountered factors associated with death related to anesthesia. In the preoperative setting, the majority of antihypertensive medications should be continued until surgery. Only renin-angiotensin system antagonists may be stopped. Hypertension, especially in the case of mild to moderate hypertension, is not a cause for delaying surgery. During the intraoperative period, anesthesia leads to hypotension. Hypotension episodes should be promptly treated by intravenous vasopressors, and according to their etiology. In the postoperative setting, hypertension predominates. Continuation of antihypertensive medications and postoperative care may be insufficient. In these cases, intravenous antihypertensive treatments are used to control blood pressure elevation. Keywords: hypertension, hypotension, perioperative, blood pressure control

Full Text Available Background: Hypertension is the main independent cardiovascular risk factor. However, there are additional factors that induce organic damage. Aim: To assess the association between hyperinsulinemia, ventricular hypertrophy and left ventricular diastolic function. Patients and Methods: Seventy-four patients aged 30 to 65 years, with mild or moderate systemic hypertension, with overweight or mild obesity and normal glucose tolerance curve (GTC, were studied. Serum insulin was measured during GTC. The maximum levels of insulin and glucose were observed 60 minutes after the oral glucose load and they were expressed as rG/1. Patients were stratified in three groups according to their glucose and insulin fasting levels (I0 and post-glucose challenge levels (rG/I: Group 1 (normoinsulinemic patients I0 2 (2.45+0.4. Group 2 (post-prandial hyperinsulinemic patients I0 17 mU/mL and <1 (0.7+0.3. Left ventricular mass and its diastolic function were measured by Doppler echocardiography. Results: No differences in blood pressure or age were observed between groups. There was a negative correlation between ventricular mass and rG/1 (r =-0.282, p =0.015. Left ventricular diastolic dysfunction was significantly more deteriorated in group 3, as compared with group 1 (p <0.001 ANOVA. There was a significant correlation between g/GI and diastolic dysfunction (r =0.232 p =0.047. Conclusions: Fasting, post challenge hyperinsulinemia and a rG/I <1 are associated with higher ventricular mass and left ventricular diastolic dysfunction, independent of blood pressure and age (Rev Méd Chile 2007; 135: 1125-31

Full Text Available Background/Aim. Hypertension is a known predictor of proximal aortic dissection, but it is not commonly present in these patients on presentation. The associations between ascending aorta with left ventricular hypertrophy, cardiovascular risk factors and coronary atherosclerosis, and outcome of these patients are not fully elucidated. Methods. This retrospective study included 55 consecutive patients with acute type A aortic dissection treated surgically in our institution during the last 2 years. The diagnosis was based on imaging studies. Diameter of ascending aorta was measured with echocardiography. Results. The mean age of the patients was 55.4 ± 12.19 years, and 72.7% were men. A history of arterial hypertension was present in 76.4% of the patients. Maximal ascending aorta diameter was 4.09 ± 0.59 cm, while patients with frank aneurysm accounted for 5.5%. Systolic blood pressure on admission was < 150 mmHg in 58.2% of the patients. Diastolic blood pressure on admission was < 90 mmHg in 54.5% of the patients. Mean arterialpressure on admission was 104.9 ± 24.6 mmHg. No correlations were demonstrated between maximal ascending aorta diameter and diameter of the left ventricular wall, any obtained risk factor and with coronary artery atherosclerosis (p > 0.05. After six months 11 (20% patients died, while intrahospital mortality was 72%. According to logistic regression analysis which included traditional risk factors, echo parameters, coronary artery disease and logistic euro scor, mean arterial blood pressure was the independent predictor of a six-month mortality [RR 0.956; CI (0.918-0.994 ; p = 0.024]. Conclusion. In our population the acute type A aortic dissection occurred rarely in the setting of frank ascending aortic aneurysms > 5.0 cm. The majority of patients had a history of arterial hypertension. A history of arterial hypertension was not associated with maximal ascending aorta diameter. Mean arterial blood pressure was the independent predictor of a six-months mortality.

Pressure myograph systems are exquisitely useful in the functional assessment of small arteries, pressurized to a suitable transmural pressure. The near physiological condition achieved in pressure myography permits in-depth characterization of intrinsic responses to pharmacological and physiological stimuli, which can be extrapolated to the in vivo behavior of the vascular bed. Pressure myograph has several advantages over conventional wire myographs. For example, smaller resistance vessels can be studied at tightly controlled and physiologically relevant intraluminal pressures. Here, we study the ability of 3rd order mesenteric arteries (3-4 mm long), preconstricted with phenylephrine, to vaso-relax in response to acetylcholine. Mesenteric arteries are mounted on two cannulas connected to a pressurized and sealed system that is maintained at constant pressure of 60 mmHg. The lumen and outer diameter of the vessel are continuously recorded using a video camera, allowing real time quantification of the vasoconstriction and vasorelaxation in response to phenylephrine and acetylcholine, respectively. To demonstrate the applicability of pressure myography to study the etiology of cardiovascular disease, we assessed endothelium-dependent vascular function in a murine model of systemic hypertension. Mice deficient in the ?1 subunit of soluble guanylate cyclase (sGC?1-/-) are hypertensive when on a 129S6 (S6) background (sGC?1-/-S6) but not when on a C57BL/6 (B6) background (sGC?1-/-B6). Using pressure myography, we demonstrate that sGC?1-deficiency results in impaired endothelium-dependent vasorelaxation. The vascular dysfunction is more pronounced in sGC?1-/-S6 than in sGC?1-/-B6 mice, likely contributing to the higher blood pressure in sGC?1-/-S6 than in sGC?1-/-B6 mice. Pressure myography is a relatively simple, but sensitive and mechanistically useful technique that can be used to assess the effect of various stimuli on vascular contraction and relaxation, thereby augmenting our insight into the mechanisms underlying cardiovascular disease. PMID:23770818

BACKGROUND: Diastolic dysfunction is frequently seen after myocardial infarction and is characterized by a disproportionate increase in filling pressure during exercise to maintain stroke volume. We hypothesized that sildenafil would reduce filling pressure during exercise in patients with diastolic dysfunction after myocardial infarction. METHODS AND RESULTS: Seventy patients with diastolic dysfunction and near normal left ventricular ejection fraction on echocardiography were randomly assigned sildenafil 40 mg thrice daily or matching placebo for 9 weeks. Before randomization and after 9 weeks of treatment patients underwent simultaneous echocardiography and right heart catheterization at rest and during exercise. Primary end point was pulmonary capillary wedge pressure, and secondary end points comprised cardiac index and pulmonary arterialpressure at rest and during exercise after 9 weeks. After 9 weeks there were no differences in pulmonary capillary wedge pressure at rest (13±4 versus 13±3 mm Hg, P=0.25) or at peak exercise (35±8 mm Hg versus 31±7 mm Hg, P=0.07). However, with treatment cardiac index increased at rest (P=0.006) and peak exercise (P=0.02) in the sildenafil group, and systemic vascular resistance index (resting, P=0.0002; peak exercise, P=0.007) and diastolic blood pressure (resting, P=0.005; peak exercise, P=0.02) were lower in the sildenafil group. Resting left ventricular end-diastolic volume index increased (P=0.001) within the sildenafil group but was unchanged in the placebo group. CONCLUSIONS: Sildenafil did not decrease filling pressure at rest or during exercise in post-myocardial infarction patients with diastolic dysfunction. However, there were effects on secondary end points, which require further studies.

The effect of repeated (3 to 10 second) and transient (15 to 75 second) abrupt coronary occlusion on the global and regional chamber stiffness was studied in nine patients undergoing angioplasty of a single proximal left anterior descending coronary artery stenosis. The left ventricular high fidelity pressure and volume relation was obtained before and after the procedure as well as during coronary occlusion, after 20 seconds (n = 9) and after 50 seconds (n = 5). During ischemia, there was an...

Full Text Available The aim of the study was to determine correlation between arterial blood pressure daily rhythm and daily profile of arterial stiffness in male patients with chronic obstructive pulmonary disease (COPD and arterial hypertension. Materials et methods: Prospective investigation comprised 45 male patients with COPD and arterial hypertension. Individuals of 40 years younger and 80 years elder, patients with diabetes, stroke, angina pectoris, or heart infarction, vascular diseases, and exacerbation of chronic disease, bronchial and pulmonary diseases of other etiology were excluded from the analyses. Comparison group included 47 patients with essential arterial hypertension and without chronic respiratory diseases closely similar on general parameters with patients from main clinical series. Twenty-four-hour arterial blood pressure monitoring (ABPM and daily arterial stiffness monitoring were performed using BPLab® MnSDP-2 apparatus (Petr Telegin, Russian Federation. Results: Patients with COPD combined with arterial hypertension with raised arterial stiffness measures prevail over individuals in essential hypertension group. There is pathological alteration of the ABPM circadian rhythm and raised «Pressure load» values in raised arterial stiffness group. Conclusion: We found ABPM raised parameters in patients with COPD and arterial hypertension. It confirms necessity of ABPM in daily arterial stiffness assessment in patients with COPD.

A transcatheter technique for administering drugs preferentially to the canine left coronary circulation is described. The method involves pulsed, diastolic, small-volume (0.2 ml) injections through a specially designed aortic cusp catheter. In order to evaluate preferential delivery to the coronary circulation, papaverine was administered using this technique and compared to intravenous delivery. Left circumflex and carotid arterial blood flow, as well as systemic arterialpressure, were sim...

OBJECTIVE--To examine the hypothesis that a J curve relation between blood pressure and death from coronary heart disease is confined to high risk subjects with myocardial infarction. DESIGN--Cohort longitudinal epidemiological study with biennial examinations since 1950. SETTING--Framingham, Massachusetts, USA. SUBJECTS--5209 subjects in the Framingham study cohort followed up by a person examination approach. MAIN OUTCOME MEASURES--Coronary heart disease deaths and non-cardiovascular diseas...

Full Text Available Resistant hypertension (RHTN) is a multifactorial disease characterized by blood pressure (BP) levels above goal (140/90 mmHg) in spite of the concurrent use of three or more antihypertensive drugs of different classes. Moreover, it is well known that RHTN subjects have high prevalence of left ventr [...] icular diastolic dysfunction (LVDD), which leads to increased risk of heart failure progression. This review gathers data from studies evaluating the effects of phosphodiesterase-5 (PDE-5) inhibitors (administration of acute sildenafil and short-term tadalafil) on diastolic function, biochemical and hemodynamic parameters in patients with RHTN. Acute study with sildenafil treatment found that inhibition of PDE-5 improved hemodynamic parameters and diastolic relaxation. In addition, short-term study with the use of tadalafil demonstrated improvement of LVDD, cGMP and BNP-32 levels, regardless of BP reduction. No endothelial function changes were observed in the studies. The findings of acute and short-term studies revealed potential therapeutic effects of IPDE-5 drugs on LVDD in RHTN patients.

Full Text Available Resistant hypertension (RHTN) is a multifactorial disease characterized by blood pressure (BP) levels above goal (140/90 mmHg) in spite of the concurrent use of three or more antihypertensive drugs of different classes. Moreover, it is well known that RHTN subjects have high prevalence of left ventr [...] icular diastolic dysfunction (LVDD), which leads to increased risk of heart failure progression. This review gathers data from studies evaluating the effects of phosphodiesterase-5 (PDE-5) inhibitors (administration of acute sildenafil and short-term tadalafil) on diastolic function, biochemical and hemodynamic parameters in patients with RHTN. Acute study with sildenafil treatment found that inhibition of PDE-5 improved hemodynamic parameters and diastolic relaxation. In addition, short-term study with the use of tadalafil demonstrated improvement of LVDD, cGMP and BNP-32 levels, regardless of BP reduction. No endothelial function changes were observed in the studies. The findings of acute and short-term studies revealed potential therapeutic effects of IPDE-5 drugs on LVDD in RHTN patients.

Full Text Available Arterial diseases, promoted by alterations in arterial wall properties, are among the main causes of mortality. Mechanical stresses of the arterial wall caused by pulsatile luminal pressure define arterial function in normal and pathological conditions. This study aims to determine dynamic stress distribution in the arterial wall subjected to physiological pressure waveforms. Finite element models of a typical artery are developed to evaluate Von Misses stress in the arterial wall due to physiological pressure waveforms and with differing mechanical properties. Mechanical parameters include Young's modulus of elasticity, non-linear stress-strain relationship and visco-elastic parameter. The appropriate boundary conditions are allocated to allow radial expansion. Application of physiological pulsatile pressure results in stress waves with the values and waveforms markedly influenced by mechanical properties of the arterial wall and blood pressure pulse. Elevated elastic modulus of the arterial wall results in significant increase in maximum stress. Viscoelastic property leads to reduction of the peak stress and smoothening of the stress waveform. The pressure waveform is also a major parameter affecting the stress pattern in arterial wall. Hypertensive arteries result in higher and sharper stress waves not only because of a higher systolic value but also because of the sharper waveform. The combination of these parameters produces the resultant stress pattern in the arterial wall.

Objectives: To characterize the effects of regular Roselle ingestion on blood pressure and left ventricular hypertrophy (LVH) in patients with established moderate essential hypertension. Methods: This non-randomized quasi-experimental study was conducted in Kafr El-Shaikh, Egypt, for 8 weeks, from September 2012 to November 2012. The effects of a 4-week period of regular Roselle ingestion followed by a 4-week recovery period on systolic blood pressure (SBP), diastolic blood pressure (DBP),...

Our goal is to test the effect of both rare and common variants in a blood pressure study. We use a pathway-based approach, gene-set enrichment analysis, to search for related genes affecting 4 phenotypes: systolic blood pressure, diastolic blood pressure, the difference between each of them and mean arterialpressure, which is a weighted linear combination of systolic and diastolic blood pressure. Using the real Genetic Analysis Workshop 18 data, we consider both rare and common variants in ...

In the choroid, there is evidence that blood flow does not only depend on ocular perfusion pressure (OPP), but also on absolute mean arterialpressure (MAP) and intraocular pressure (IOP). The present study included 40 healthy subjects to investigate whether such behavior is also found in the optic nerve head (ONH). The ONH blood flow (ONHBF) was studied using laser Doppler flowmetry during a separate increase in IOP and MAP as well as during a combined elevation. Mean arterialpressure was i...

Low levels (i.e., ?20 mmHg) of lower body negative pressure (LBNP) have been utilized to unload “selectively” cardiopulmonary baroreceptors in humans, since steady-state mean arterialpressure and heart rate (HR) have been found unchanged at such levels. However, transient reductions in blood pressure (BP), followed by reflex compensation, may occur without detection, which could unload arterial baroreceptors. The purposes of this study were to test the hypothesis that the arterial baro...

Full Text Available The ArterialPressure Waveform (APW can provide essential information about arterial wall integrity and arterial stiffness. Most of APW analysis frameworks individually process each hemodynamic parameter and do not evaluate inter-dependencies in the overall pulse morphology. The key contribution of this work is the use of machine learning algorithms to deal with vectorized features extracted from APW. With this purpose, we follow a five-step evaluation methodology: (1 a custom-designed, non-invasive, electromechanical device was used in the data collection from 50 subjects; (2 the acquired position and amplitude of onset, Systolic Peak (SP, Point of Inflection (Pi and Dicrotic Wave (DW were used for the computation of some morphological attributes; (3 pre-processing work on the datasets was performed in order to reduce the number of input features and increase the model accuracy by selecting the most relevant ones; (4 classification of the dataset was carried out using four different machine learning algorithms: Random Forest, BayesNet (probabilistic, J48 (decision tree and RIPPER (rule-based induction; and (5 we evaluate the trained models, using the majority-voting system, comparatively to the respective calculated Augmentation Index (AIx. Classification algorithms have been proved to be efficient, in particular Random Forest has shown good accuracy (96.95% and high area under the curve (AUC of a Receiver Operating Characteristic (ROC curve (0.961. Finally, during validation tests, a correlation between high risk labels, retrieved from the multi-parametric approach, and positive AIx values was verified. This approach gives allowance for designing new hemodynamic morphology vectors and techniques for multiple APW analysis, thus improving the arterial pulse understanding, especially when compared to traditional single-parameter analysis, where the failure in one parameter measurement component, such as Pi, can jeopardize the whole evaluation.

Full Text Available In our study 100 consecutive non-valvular permanent atrial fibrillation patients with NYHA I – III heart failure, 43 - 86 years old (65 men and 35 women were examined. Control group consisted of 30 patients with arterial hypertension and coronary artery disease matched by age, sex with basic group. Relationship of NT-proBNP with echocardiographic parameters of left heart were studied. Transthoracic echocardiography with tissue doppler measurements were performed on echocardiograph “SONOS 7500”. For left ventricular filling pressure assessment ratio Em/Ea was used due to its diagnostic value in atrial fibrillation (regardless of left ventricular ejection fraction. Mean left ventricular filling pressure was increased in patients with heart failure: in atrial fibrillation group and controls as well. In comparison with controls atrial fibrillation group was more likely to have higher both systolic and diastolic left atrial square and volume. According to Em/Ea in 95% of patients with non-valvular atrial fibrillation high left ventricular filling pressure was observed, this testifies to diastolic dysfunction. This parameter correlated well with left atrial square and volume during systole and diastole. Correlation between NT pro-BNP level and NYHA class of heart failure, left ventricular filling pressure was determined in patients with atrial fibrillation. Tissue doppler echocardiography makes it possible to diagnose left ventricular diastolic dysfunction in atrial fibrillation patients.

Vascular smooth muscle cell (VSMC) proliferation remains a major cause of veno-arterial graft failure. We hypothesised that exposure of venous SMCs to arterialpressure would increase KLF5 expression and that of cell cycle genes. Porcine jugular veins were perfused at arterial or venous pressure in the absence of growth factors. The KLF5, c-myc, cyclin-D and cyclin-E expression were elevated within 24 h of perfusion at arterialpressure but not at venous pressure. Arterialpressure also reduced the decline in SM-myosin heavy chain expression. These data suggest a role for KLF5 in initiating venous SMCs proliferation in response to arterialpressure.

Vascular smooth muscle cell (VSMC) proliferation remains a major cause of veno-arterial graft failure. We hypothesised that exposure of venous SMCs to arterialpressure would increase KLF5 expression and that of cell cycle genes. Porcine jugular veins were perfused at arterial or venous pressure in the absence of growth factors. The KLF5, c-myc, cyclin-D and cyclin-E expression were elevated within 24 h of perfusion at arterialpressure but not at venous pressure. Arterialpressure also reduced the decline in SM-myosin heavy chain expression. These data suggest a role for KLF5 in initiating venous SMCs proliferation in response to arterialpressure.

Full Text Available Systemic arterial blood pressures were measured in 30 dogs with acute babesiosis, 10 each with mild uncomplicated, severe uncomplicated and complicated disease. Ten healthy dogs were used as controls. Hypotension was defined as more than 3 standard deviations below the control mean. Normal mean pressures (Â±SD were: systolic arterialpressure 151 (Â±11 mm Hg, diastolicarterialpressure 89 (Â±8 mm Hg and mean arterialpressure 107 (Â±10 mmHg. Hypotension was the most frequent abnormality, and increased strikingly in incidence as disease severity increased, with 5/10 dogs in the complicated group being hypotensive for systolic, diastolic and mean arterialpressures, compared with 2/10 in the severe uncomplicated group and 0/10 in the mild uncomplicated group. Systolic, diastolic and mean arterialpressures in the complicated group and severe uncomplicated group, and systolic pressure in the mild uncomplicated group, were significantly lower than in the controls. There were no significant relationships between arterialpressures and age, pulse rate, respiratory rate, temperature, mucous membrane colour or haematocrit. There was a significant negative correlation between arterialpressures and white cell and immature neutrophil counts. Arterialpressures differed significantly between dogs that were clinically collapsed and those that were not, but not between survivors and non-survivors. Pulse pressure (systolic - diastolic was low in 7/10 complicated, 1/10 mild uncomplicated, and 1/10 severe uncomplicated cases, and differed significantly between the complicated and control groups. The high incidence of hypotension in clinically severe babesiosis has important implications for therapy.

The advent of vascular diseases, such as hypertension and atherosclerosis, is associated to significant alterations in the physical properties of arterial vessels. Evaluation of arterial biomechanical behaviour is related to the assessment of three representative indices: arterial compliance, arterial distensibility and arterial stiffness index. Elasticity is the most important mechanical property of the arterial wall, whose natures is strictly non-linear. Intervention of elastin and collagen fibres, passive constituent elements of the arterial wall, is related to the applied wall stress level. Concerning this, appropriate tools are required to analyse the temporal dynamics of the signals involved, in order to characterize the whole phenomenon. Fractal geometry can be mentioned as one of those techniques. The aim of this study consisted on arterialpressure and diameter signals processing, by means of nonlinear techniques based on fractal geometry. Time series morphology was related to different arterial stiffness states, generated by means of blood flow variations, during experiences performed in vitro.

Full Text Available Background/Aim. Left ventricular hypertrophy (LVH, apart from arterial hypertension, is a risk factor for electrophysiologic heart condition disorder and sudden cardiac death. The aim of this study was to examine a relationship between complex ventricular arrhythmias and parameters of 24-hour ambulatory blood pressure monitoring in the patients with arterial hypertension and left ventricular hypertrophy (LVH, as well as their prognostic significance during a five-year follow-up. Methods. Ninety patients with arterial hypertension and LVH were included in this study (mean age 55.2±8.3 years. There were 35 healthy people in the control group (mean age 54.5±7.1 years. Left ventricular mass index was 171.9±32.4 g/m2 in the LVH group and 102.4±13.3 g/m2 in the control group. Clinical examination, echocardiogram, 24-hour ambulatory blood pressure monitoring and 24-hour holter monitoring were done in all of the examined persons. Ventricular arrhythmias were classified by the Lown classification. Results. In the LVH group there were 54 (60.0% of the patients with ? III Lown class. The best predictor of a Lown class were left ventricular mass index by using multivariate stepwise regression analyses (? = 0.212; p < 0.05 and small decrease of diastolic blood pressure during the night (? = -0.293; p < 0.01. The main predictor of bad prognosis was left ventricular mass index during a five year follow-up (? = 0.302; p < 0.01, for stepwise regression model: F = 8.828; p < 0.01, adjusted R2 = 0.091. Conclusion. Left ventricular arrhythmias are frequent in patients with lower decrease of blood pressure during the night. There was no correlation between the degree of ventricular arrhythmias and parameters from 24-hour blood pressure monitoring and a five-year prognosis in the patients with arterial hypertension and LVH. A bad five-year follow-up outcome of hypertensive disease depends on left ventricular mass index.

Objective: Examine pulmonary artery systolic pressure (PASP) response to exercise in isolated borderline and mild to moderate pulmonary arterial hypertension (PAH).Methods: Doppler stress echocardiography was performed in 32 healthy volunteers with resting PASP of 29 mm Hg or less, 39 with resting PASP between 30 and 40 mm Hg, and 7 with resting PASP between 41 and less than 60 mm Hg. All subjects had otherwise normal echocardiograms.Results: Rate of increase in PASP with exercise was posit...

The objective of this study was to examine the effect on blood pressure (BP) and isobaric arterial elasticity (AE), as a measure of arterial health, of a commercial mixture of conjugated linoleic acids (CLA) and of milk fat produced through livestock feeding to have a high content of vaccenic acid (VA). Healthy young men (n = 60) with a BMI of 22.5 +/- 2 kg/m(2) (mean +/- SD) participated in this double-blind, randomized, 5-wk, parallel intervention study. The participants substituted 115 g of their daily fat intake with fat from 1 of 3 test diets: 1) CLA-diet rich in CLA (4.7 g/d of c9, t11- and t10, c12-CLA isomers in equal amounts); 2) VA-diet rich in VA (3.6 g/d); or 3) C-diet, a control diet with a low content of VA and CLA. All test diets were based on milk fat. BP and AE (measured by an oscillometric method) were measured before and after the intervention period. The effects of the test diets did not differ on any outcome variable: e.g., systolic- and diastolic blood pressure (SBP and DBP), pulse pressure (PP), isobaric arterial compliance (AC), distensibility (AD), or volume (AV). In conclusion, diets rich in milk fat and either CLA or VA have no effect on BP or AE indices in healthy young men compared with a control diet.

The large, radial periodic motion of an artery subjected to a dynamic inner pressure is studied through the use of finite deformation theory of elastic materials. The artery is assumed to behave as an isotropic, homogeneous and incompressible elastic material. Expressions for intramural pressure and wall stresses are obtained as a function of the large periodic motion. Dynamic effects are shown to both increase the diastolicpressure and decrease the systolic pressure. It is also shown that, under certain conditions, the artery may experience a negative intramural pressure, in which case the artery may collapse. The present study predicts very large circumferential stress and stress gradients which might lead the artery to arteriosclerosis. PMID:6643535

Full Text Available Abstract Left ventricular (LV diastolic dysfunction (DD and diastolic heart failure (HF, that is symptomatic DD, are due to alterations of myocardial diastolic properties. These alterations involve relaxation and/or filling and/or distensibility. Arterial hypertension associated to LV concentric remodelling is the main determinant of DD but several other cardiac diseases, including myocardial ischemia, and extra-cardiac pathologies involving the heart are other possible causes. In the majority of the studies, isolated diastolic HF has been made equal to HF with preserved systolic function (= normal ejection fraction but the true definition of this condition needs a quantitative estimation of LV diastolic properties. According to the position of the European Society of Cardiology and subsequent research refinements the use of Doppler echocardiography (transmitral inflow and pulmonary venous flow and the new ultrasound tools has to be encouraged for diagnosis of DD. In relation to uncertain definitions, both prevalence and prognosis of diastolic heart failure are very variable. Despite an apparent lower death rate in comparison with LV systolic HF, long-term follow-up (more than 5 years show similar mortality between the two kinds of HF. Recent studies performed by Doppler diastolic indexes have identified the prognostic power of both transmitral E/A ratio 1.5 (restrictive patterns. The therapy of LV DD and HF is not well established but ACE-inhibitors, angiotensin inhibitors, aldosterone antagonists and ?-blockers show potential beneficial effect on diastolic properties. Several trials, completed or ongoing, have been planned to treat DD and diastolic HF.

Introduction Atherosclerotic renal artery stenosis (ARAS) is associated with uncontrolled hypertension and chronic renal failure. Aim To evaluate the influence of gender and presence of chronic renal failure on the outcomes of percutaneous transluminal renal artery stenting (PTRAS) due to atherosclerosis. Material and methods A total of 28 ARAS patients underwent PTRAS and 36 stents were placed. Basal characteristics, laboratory data and blood pressure of patients were recorded. The differences between genders and improvement/deterioration of renal functions and blood pressure were analyzed. The predictors of outcomes were determined. Results Baseline characteristics were similar between men and women. Significant improvement of systolic and diastolic blood pressure control was achieved after PTRAS (153.04 ±17.07 mm Hg vs. 124.75 ±11.40 mm Hg, p = 0.001 and 92.50 ±10.76 mm Hg vs. 77.54 ±8.23 mm Hg, p < 0.001, respectively). Although mean estimated glomerular filtration rate (eGFR) and creatinine levels did not significantly improve at the 6-month follow-up visit compared to baseline values, of the 28 patients 13 (46.4%) patients had improvement of renal functions. Conclusions Our results suggest that PTRAS is a safe procedure and may offer blood pressure control but beneficial effects of PTRAS on renal function may be anticipated in a selected group of patients, especially those with a low eGFR. PMID:24570723

Previous research suggests that elevated pulse pressure (PP) is a risk factor for atrial fibrillation (AF) independently of mean arterialpressure (MAP). PP may serve as an indirect measure of aortic stiffness (reduced distensibility), but whether directly measured aortic distensibility is related to risk for AF has not yet been studied. This analysis included 6,630 participants aged 45 to 84 years from the Multi-Ethnic Study of Atherosclerosis. At baseline, blood pressure and other relevant covariates were measured using standardized protocols. Magnetic resonance imaging-based aortic distensibility was measured in 3,441 participants. Incident AF was identified from hospitalization discharge codes and Medicare claims. Multivariate Cox models were used to estimate the association of blood pressure components and aortic distensibility with AF risk. During a mean follow-up of 7.8 years, 307 AF events (137 among those with aortic distensibility measurements) were identified. In multivariate-adjusted models simultaneously including MAP and PP, each 1-SD increase in PP was associated with a 29% increased risk of AF (95% confidence interval 5% to 59%, p = 0.02), with MAP not being associated with increased AF risk. Overall, aortic distensibility was not consistently associated with AF risk: after removing outliers, each 1-SD increase in aortic distensibility was associated with a 9% increased risk of AF (95% confidence interval -22% to 51%, p = 0.63). In conclusion, in this large community-based cohort, we found that PP, but not MAP or aortic distensibility, was a significant risk factor for AF, emphasizing the importance of PP when assessing the risk for developing AF. Our results cast doubt on the clinical utility of aortic distensibility as a predictor for the development of AF. PMID:24996553

Obesity, elevated blood pressure (BP) and arterial stiffness are risk factors for cardiovascular disease. A strong relationship exists between obesity and elevated BP in both children and adults. Obesity and elevated BP in childhood track into adult life increasing the risk of cardiovascular disease in adulthood. Ambulatory BP is the most precise measure to evaluate the BP burden, whereas carotid-femoral pulse wave velocity (cfPWV) is regarded as the gold standard for evaluating arterial (i.e. aortic) stiffness. These measures might contribute to a better understanding of obesity's adverse impact on the cardiovascular system, and ultimately a better prevention and treatment of childhood obesity. The overall aim of the present PhD thesis is to investigate arterial stiffness and 24-hour BP in obese children and adolescents, and evaluate whether these measures are influenced by weight reduction. The present PhD thesis is based on four scientific papers. In a cross-sectional design, 104 severe obese children and adolescents with an age of 10-18 years were recruited when newly referred to the Children's Obesity Clinic, Holbæk University Hospital, and compared to 50 normal weighted age and gender matched control individuals. Ambulatory BP was measured, and cfPWV was investigated in two ways in respect to the distance measure of aorta; the previously recommended length - the so called subtracted distance, and the currently recommended length - the direct distance. In a longitudinal design, the obese patients were re-investigated after one-year of lifestyle intervention at the Children's Obesity Clinic in purpose of reducing the degree of obesity. In the cross-sectional design, the obese group had higher measures of obesity, while matched for age, gender and height, when compared to the control group. In the longitudinal design, 74% of the 72 followed up obese patients experienced a significant weight reduction. CfPWV was dependent on the method used to measure the length of the aorta. The subtracted distance was not consistent in its relation to height in the obese and the control group. Opposite, the direct distance was consistent in its relation to height in the two groups. Therefore, cfPWV using the direct distance (cfPWV-direct) was regarded as the appropriate measure of arterial stiffness. CfPWV-direct was reduced in the obese group after adjustment for known confounders. In the longitudinal design, weight reduction across one year did not have an impact on cfPWV-direct in the obese patients. In fact, cfPWV-direct was higher at follow-up, which was explained by the increased age and partly by changes in BP and heart rate. The obese group had a relatively higher night- than day-time BP when compared to the control group. The obesity-related elevated night-time BP was independent of arterial stiffness and insulin resistance. Although night-time systolic BP was related to arterial stiffness and tended to be related to insulin resistance, insulin resistance and arterial stiffness were not related. In the longitudinal design, changes in anthropometric obesity measures across one year were associated with changes in 24-hour, day- and night-time BP, and consistent when evaluated in standardised values that accounted for growth. No association was found between changes in anthropometric obesity measures and changes in clinic BP. In conclusion, the results suggest that obesity in children is not "yet" associated with structural changes in aorta when evaluated with the appropriate new method of cfPWV. In this respect, weight reduction did not have an impact on arterial stiffness. The ambulatory BP, namely the night-time BP, was elevated in the obese patients, whereas changes in anthropometric obesity measures were related to changes in ambulatory BP but not to changes in clinic BP. In perspective, it is reassuring that weight changes are accompanied with a change in 24-hour BP as ambulatory BP is the most precise measure to evaluate the BP burden, and it emphasises the use of 24-hour ambulatory BP measurements in childr

Arteries can buckle axially under applied critical buckling pressure due to a mechanical instability. Buckling can cause arterial tortuosity leading to flow irregularities and stroke. Genetic mutations in elastic fiber proteins are associated with arterial tortuosity in humans and mice, and may be the result of alterations in critical buckling pressure. Hence, the objective of this study is to investigate how genetic defects in elastic fibers affect buckling pressure. We use mouse models of human disease with reduced amounts of elastin (Eln+/-) and with defects in elastic fiber assembly due to the absence of fibulin-5 (Fbln5-/-). We find that Eln+/- arteries have reduced buckling pressure compared to their wild-type controls. Fbln5-/- arteries have similar buckling pressure to wild-type at low axial stretch, but increased buckling pressure at high stretch. We fit material parameters to mechanical test data for Eln+/-, Fbln5-/- and wild-type arteries using Fung and four-fiber strain energy functions. Fitted parameters are used to predict theoretical buckling pressure based on equilibrium of an inflated, buckled, thick-walled cylinder. In general, the theoretical predictions underestimate the buckling pressure at low axial stretch and overestimate the buckling pressure at high stretch. The theoretical predictions with both models replicate the increased buckling pressure at high stretch for Fbln5-/- arteries, but the four-fiber model predictions best match the experimental trends in buckling pressure changes with axial stretch. This study provides experimental and theoretical methods for further investigating the influence of genetic mutations in elastic fibers on buckling behavior and the development of arterial tortuosity. PMID:25771258

We investigated water drinking and arterial blood pressure responses to intravenous infusions of ANG II in young (4 mo), middle-aged adult (12 mo), and old (29 mo) male Brown Norway rats. Infusions of ANG II began with arterial blood pressure either at control levels or at reduced levels following injection of the vasodilator minoxidil. Under control conditions, mean arterialpressure (MAP) in response to ANG II rose to the same level for all groups, and middle-aged and old rats drank as much...

Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC) measurement by the pulmonary artery catheter (PAC). However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterialpressure-based cardiac output (COAP) device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA) only requires access to the radial or femoral artery using...

Full Text Available Background: Cardiovascular problems including arterial hypertension, coronary artery diseases, congestive heart failure are prevalent among chronic hemodialyzed patients. Ultrafiltration of hemodialyzed patient's serum, which culminating in intravascular volume reduction, is frequently used during hemodialysis. One of the restrictions of the echocardiographic evaluation of the diastolic heart function is the intravascular volume dependency of some echocardiographic parameters. In this study we have evaluated the volume dependency of certain echocardiography parameters in chronically hemodialyzed patients. Methods: Thirteen patients undergoing chronic hemodialysis in Ghaem Hospital Hemodialysis Center in Mashhad, Iran, were evaluated one hour before and immediately after hemodialysis for the following: all diastolic echocardiographic parameters, left ventricular function, left ventricular systolic function, inferior vena cava (IVC diameter and IVC collapsibility with inspiration, and systolic and diastolic blood pressure. The echocardiographic parameters were analyzed using the paired Student's t-test. Results: With hemodialysis, there was no significant change in left ventricular function, A wave amplitude and E/F slope, however, there was a significant reduction of the E wave amplitude, increment in E wave deceleration time (p= 0.001, t=-4.14 and a decrease in the E/A ratio (p=0.03, t=2.46. Tissue Doppler echocardiography showed no significant change in mitral annular diastolic motion, E'/A' waves, with hemodialysis (p=0.728, t= - 0.356, although there was a reduction of the E/E' ratio. Conclusion: Tissue Doppler imaging and color M-mode echocardiographic parameters are independent of the intravascular value status. With no change associated with hemodialysis, these parameters can be used as reliable criteria for evaluating ventricular diastolic function even when the volume status varies. Hekmat R. *1"nTalebi S.2"nMohebati.M.2"n1- Department of Nephrology"n2- Department of Cardiology"nMashad University of Medical"nSciences

Following sinoaortic denervation, which eliminates arterial baroreceptor input into the brain, there are slowly developing adaptations that abolish initial sympathetic activation and hypertension. In comparison, electrical stimulation of the carotid sinus for 1 wk produces sustained reductions in sympathetic activity and arterialpressure. However, whether compensations occur subsequently to diminish these responses is unclear. Therefore, we determined whether there are important central and/...

Arterial Blood Pressure wave monitoring is considered to be important in assessment of cardiovascular system. We developed a novel pulse wave detection system using low frequency specific piezoelectric material as pressure wave sensor. The transducer detects the periodic change in the arterial wall diameter produced by pressure wave and the amplified signal after integration represents the pressure wave. The signal before integration is proportional to the rate of change of pressure wave and it not only reproduces the pressure waveform faithfully, but also its sharper nature helps to reliably detect the heart period variability (HPV). We have studied the position-specific (e.g. over carotid or radial artery) nature of change of this pulse wave signal (shape and amplitude) and also the changes at different physiological states.

Early detection of coronary artery disease (CAD) using the acoustic approach, a noninvasive and cost-effective method, would greatly improve the outcome of CAD patients. To detect CAD, we analyze diastolic sounds for possible CAD murmurs. We observed diastolic sounds to exhibit 1/f structure and developed a new method, path length entropy (PLE) and a scaled version (SPLE), to characterize this structure to improve CAD detection. We compare SPLE results to Hurst exponent, Sample entropy and Mu...

Full Text Available OBJETIVO: Comparar a pressão arterial (PA basal e as respostas a estímulos pressóricos de filhos de normotensos e filhos de hipertensos. MÉTODOS: Foram examinados 32 adolescentes, do sexo masculino, brancos, na faixa etária entre 13 e 18 anos, sendo que 16 eram filhos de hipertensos e 16 filhos de normotensos. Para cada indivíduo foi aferida a PA basal seguida da aplicação de três testes pressóricos: teste do exercício isométrico com o handgrip, teste pressor ao frio e teste do exercício aritmético mental. Para a aferição da PA foi utilizado um dispositivo oscilométrico, digital, previamente calibrado. RESULTADOS: Os filhos de hipertensos exibiram valores basais de PA, tanto sistólica quanto diastólica, maiores que os filhos de normotensos (pPURPOSE: To compare cardiovascular reactivity in adolescents with and without family history of hypertension. METHODS: Thirty two subjects, males, students, aging between 13 to 18 years old were examined. One half of them had no family history of hypertension and the other half had at least one hypertensive parent. Basal blood pressure level was obtained before the application of the following selected tests: isometric handgrip exercise test, cold pressor test and arithmetic mental stress test. The blood pressure values were obtained by a digital, oscilometric device, previously calibrated. RESULTS: The subjects with family history of hypertension exhibited higher basal levels of both systolic and diastolic blood pressure (p<0,10. Concerning the tests applied, the subjects with family history of hypertension also exhibited higher responses, but only the response of the diastolic blood pressure to the mental stress test was statistically significant (p<0,10. CONCLUSION: Our findings point to the need of a special follow-up of children with a family history of hypertension.

The effects of long-term hypoproteinemia on renal hemodynamics, arterialpressure, and fluid volume were studied in eight conscious dogs over a 34-day period. Plasma protein concentration (PPC) was decreased by daily plasmapheresis, and the effects of decreasing and increasing sodium intake were measured. By the 12th day of plasmapheresis PPC had decreased to 2.5 g/dl from a control value of 7.2 g/dl, mean arterialpressure had decreased to 78% of control, glomerular filtration rate (GFR) was 75.2% of control, and urinary sodium excretion was decreased. By day 18 of plasmapheresis, estimated renal plasma flow (ERPF) was decreased to 60% of control due to the decreased arterialpressure and an increase in renal vascular resistance. GFR and ERPF were determined from the total clearance of [125I]iothalamate and [131I]iodohippurate. Also, plasma renin activity and plasma aldosterone concentration were both increased, and the relationship between mean arterialpressure and urinary sodium excretion was distinctly shifted to the left along the arterialpressure axis. In contradistinction to acute experiments, chronic hypoproteinemia results in decreases in GFR, ERPF, and urinary sodium excretion and has marked effects on both fluid volume and arterialpressure regulation

Systolic blood pressures at toe and ankle were measured in 459 consecutive patients with occlusive arterial disease. Fifty-eight per cent had intermittent claudication with arterial disease of all degrees of severity. Seventeen per cent complained of rest pain having toe systolic pressures below 30 mmHg, half had arterial lesions proximal to the groin. None had diabetes. Fourteen per cent non-diabetic patients had chronic ulcerations on the foot with arterial lesions similar to those in patients with rest pain. Eleven per cent diabetic patients with chronic ulcerations had less pronounced occlusive arterial disease which was located distally on the legs. A classification in three groups is suggested: (1) ischemia only during exercise; (2) ischemia at rest with or without ulcerations: and (3) diabetics with chronic ulcerations.

The clinical value of the estimation of systolic pulmonary arterypressure, based on Doppler assessment of peak tricuspid regurgitant velocity using transoesophageal echocardiography, is unclear. We studied 109 patients to evaluate the feasibility of obtaining adequate Doppler recordings, and compared Doppler estimates with values measured using a pulmonary artery catheter in a subset of 33 patients. Tricuspid regurgitation was evaluated at the mid-oesophageal level at 0-120° using Doppler echocardiography. A Doppler signal was defined as adequate if there was a ? 20° alignment and a full envelope. Doppler estimates of systolic pulmonary arterypressure within 10 mmHg and 15% of the value recorded with the pulmonary artery catheter were considered to be in sufficient agreement. Adequate Doppler signals were obtained in 64/109 (59%) patients before and 54/103 (52%) after surgery. Doppler estimates by transoesophageal echocardiography were within 10 mmHg and 15% of values recorded with the pulmonary artery catheter in 28/33 (75%) patients and 22/31 (55%) patients, respectively. In 7 (21%) patients, the echocardiographic Doppler measurement exceeded the measured systolic pulmonary arterypressure by more than 30%. Our study indicates that estimation of the systolic pulmonary arterypressure using transoesophageal Doppler echocardiography is not a reliable and clinically useful method in anaesthetised patients undergoing mechanical ventilation. PMID:25388763

Full Text Available AIM: To evaluate the short and intermediate term outcome of percutaneous transluminal renal artery angioplasty (PTRA and stenting particularly on blood pressure (BP control and renal function and to evaluate predictors of poor BP response after successful PTRA and stenting. METHODS: We conducted a prospective analysis of all patients who underwent PTRA and stenting in our institute between August 2010 to September 2012. A total number of 86 patients were underwent PTRA and renal stenting. Selective angiography was done to confirm at least 70% angiographic stenosis. The predilatation done except few cases with critical stenosis, direct stenting was done in the rest of cases. All patients received aspirin 325 mg orally, and clopidogrel 300 mg orally within 24 h before the procedure. Heparin was used as the procedural anticoagulant agent. Optimal results with TIMI-III flow obtained in all cases. Following stent placement, aspirin 150 mg orally once daily was continued for a minimum of 12 mo and clopidogrel 75 mg orally once daily for at least 4 wk. The clinical, radiological, electrocardiography, echocardiography and treatment data of all patients were recorded. The BP measurement, serum creatinine and glomerular filtration rate (GFR were recorded before the procedure and 1 and 6 mo after PTRA. RESULTS: A total of 86 patients were included in the study. The mean age of study population was 55.87 ± 11.85 years old and 67 (77.9% of patients were male. There was a significant reduction in both systolic and diastolic BP at 1 mo after the procedure: 170.15 ± 20.10 mmHg vs 146.60 ± 17.32 mmHg and 98.38 ± 10.55 mmHg vs 89.88 ± 9.22 mmHg respectively (P = 0.0000. The reduction in BP was constant throughout the follow-up period and was evident 6 mo after the procedure: 144.23 ± 18.19 and 88.26 ± 9.79 mmHg respectively (P = 0.0000. However, no improvement in renal function was observed at any time during the follow-up period. After multivariate analysis, we found male sex, low GFR (< 60 mL/min and higher baseline mean BP as a poor predictors of successful outcome on BP response after PTRA and stenting. CONCLUSION: The PTRA and stenting can be considered as an effective therapeutic intervention for improving BP control with minimal effect on renal function. The male sex, higher baseline BP and low GFR are associated with poor BP response after successful PTRA and stenting.

Full Text Available The aim of this research is to see the effect of intra-arterial infusion of leptin on blood pressure of salt loaded rabbits in vivo. Increased blood pressure was produced in rabbits by giving diets containing 8% sodium chloride for 5 weeks. Leptin in different concentrations was infused intra-arterially into rabbits fed on high salt diets and the response was compared in rabbits fed with low salt diets. High salt diets produced significant increase in blood pressure. In rabbits fed with low salt diet, leptin infused intra-arterially caused an increase in blood pressure while infusion of leptin into rabbits fed with high salt diets does not affect the blood pressure. In conclusion, salt loading to rabbits abolishes the effect of leptin on cardiovascular system. This may indicate that leptin effect on sympathetic activity is altered by high salt diets in these animals.

Respiratory variation in the systemic arterial blood pressure tracing is predictive of the change in cardiac output following volume administration. However, significant inter-individual variability exists. Animal data suggest that systemic arterial respiratory variation loses its predictive ability in the setting of right ventricular failure. Human studies suggest that patients with elevated pulmonary arterypressures are relatively unresponsive to volume administration. The current respiratory variation paradigm neglects the haemodynamic contribution of the right ventricular system. The goal of this study was to determine whether respiratory variation in the pulmonary arterial system could be attributed to intra-thoracic pressure changes. Systemic (radial) and pulmonary arterialpressure waveforms as well as all ventilatory variables were extracted from a haemodynamic database. Using a fast Fourier transformation, the ratio of respiratory (0.15-0.5 Hz) to cardiac (0.67-3 Hz) power was calculated every minute for both arterial waveforms, yielding two 'spectral power ratios' (SPoR). SPoR was compared to all available ventilatory parameters using a linear regression technique. From 19 patients 3422 min of data was analysed. There were statistically significant (p?SPoR(radial) and mean airway pressure (r?=?-0.0462) and minute ventilation (r?=?-0.130). All tested correlations between SPoR(pulmonary) and ventilatory parameters were statistically significant, with correlations ranging from 0.112-0.224 (median 0.194). The correlation between SPoR(pulmonary) and SPoR(radial) was stronger than the correlation between either measure of respiratory variation and any of the ventilatory parameters (r?=?0.342, p?0.001). Respiratory variation in the pulmonary arterial tracing does not appear to be closely related to ventilatory parameters and is more closely related to systemic arterial respiratory variation, a well-validated estimate of volume status. The observed respiratory variation in the pulmonary arterialpressure tracing may be related to cyclical changes in pre-load or after-load that occur with mechanical ventilation and may affect the predictive power of systemic arterial respiratory variation. PMID:23688057

Full Text Available Objectives. We examined the relationship between partial end-tidal CO2 (pet and mean arterialpressure in patients with traumatic hemorrhagic shock, who were receiving constant minute ventilation.Methods. In 61 patients we continuously measured pet CO2 with a capnograph, direct arterialpressure via a cannula, oxygen levels via pulse oximetry and body temperature.Results. We observed significant changes in pet CO2 (increase after volume resuscitation and a quantitative linear relationship between pet CO2 and mean arterialpressure.Conclusions. Partial end-tidal CO2 can be used as a reliable non-invasive monitoring device in patients with hemorrhagic shock when minute ventilation is relatively constant. The monitoring of pet CO2 might also be a useful guide for volume resuscitation in hemorrhagic shock, especially in the pre-hospital setting.

Purpose: To examine retinal function in relation to retinal perfusion pressure in patients with carotid artery stenosis. Methods: Thirteen patients with carotid artery stenosis without clinical eye disease underwent assessment of ophthalmic artery systolic blood pressure (OSP) by ocular pneumoplethysmography, carotid artery obstructive disease by ultrasonography, intraocular pressure by applanation tonometry, retinal perfusion by fluorescein angiography and retinal function by multifocal electroretinography (mfERG). Data analysis compared the eye on the most stenotic side with the fellow eye in the same patient. Results: Ophthalmic systolic pressure was 95.8?±?13.1?mmHg on the side with the highest degree of carotid artery stenosis (mean 94.0%) and 111.7?±?10.3?mmHg in the fellow eyes on the side with the lesser degree of stenosis (mean 33.9%). Summed mfERG implicit times (N1 and P1) were 3.4% and 2.0% longer (p?=?0.013 and 0.021), and N1 and P1 amplitudes were 18.0% and 16.0% (p?=?0.0041 and 0.020) lower in eyes on the side with the higher stenosis compared with the contralateral eyes. Shorter implicit times and higher amplitudes were correlated with higher brachial systolic arterial blood pressure (p?=?0.0028, 0.011, 0.041 for N1, P1, N2 implicit times, respectively, and p?=?0.0086, 0.016, 0.040 for N1, P1, N2 for amplitudes, respectively, corrected for OSP). Conclusion: Cone function deviation was observed in clinically healthy eyes on the side with highest degree of carotid artery stenosis and was found correlated to arterial blood pressure.

Full Text Available Aim. To assess the changes in blood pressure (BP circadian profile and variability in patients with chronic heart failure (CHF of ischemic etiology and arterial hypertension (HT due to the complex therapy including ivabradine.Material and methods. Patients (n=90 with CHF class II–III NYHA associated with stable angina II-III class and HT were examined. The patients were randomized into 3 groups depending on received drugs: perindopril and ivabradine - group 1; perindopril, bisoprolol and ivabradine - group 2; perindopril and bisoprolol - group 3. The duration of therapy was 6 months. Ambulatory BP monitoring (ABPM was assessed at baseline and after treatment.Results. More significant reduction in average 24-hours systolic BP was found in groups 1 and 2 compared to group 3 (?%: -19.4±0,4; -21.1±0.4 and -11.8±0.6, respectively as well as diastolic BP (?%: -10.6±0.6; -12.9±0.4 and -4,3±0.3, respectively and other ABPM indicators. Improvement of BP circadian rhythm was found due to increase in the number of «Dipper» patients (p=0.016. More significant reduction in average daily and night systolic and diastolic BP (p=0.001, as well as daily and night BP variability (p=0.001 was also found in patients of group 2 compared to these of group 1.Conclusion. Moderate antihypertensive effect (in respect of both diastolic and systolic BP was shown when ivabradine was included into the complex therapy of patients with ischemic CHF and HT. The effect was more pronounced when ivabradine was combined with perindopril and bisoprolol. This was accompanied by reduction in high BP daily variability and improvement of the BP circadian rhythm.

Pulse transit time has been proposed as a surrogate measure of systolic arterialpressure, as it is dependent upon arterial stiffness. Past research has shown that pulse transit time has a significant inverse relationship to systolic arterialpressure in adults; however, studies in children are limited. This study aimed to explore the relationship between systolic arterialpressure and pulse transit time in children during sleep. Twenty-five children (13.1 ± 1.6 years, 48% male) underwent overnight polysomnography (PSG) with a simultaneous recording of continuous systolic arterialpressure and photoplethysmography. Pulse transit time was calculated as the time delay between the R-wave peak of the electrocardiogram (ECG) to the 50% point of the upstroke of the corresponding photoplethysmography waveform; 500 beats of simultaneous systolic arterialpressure and pulse transit time were analysed in each sleep stage for each child. Pulse transit time was normalized to each subject's mean wake pulse transit time. The ability of pulse transit time to predict systolic arterialpressure change was determined by linear mixed-effects modelling. Significant negative correlations between pulse transit time and systolic arterialpressure were found for individual children for each sleep stage [mean correlations for cohort: non-rapid eye movement (NREM) sleep 1 and 2 r = -0.57, slow wave sleep (SWS) r = -0.76, REM r = -0.65, P model analysis demonstrated that changes in pulse transit time were a significant predictor of changes in systolic arterialpressure for each sleep stage (P model of pulse transit time-predicted systolic arterialpressure closely tracked actual systolic arterialpressure changes over time. This study demonstrated that pulse transit time was accurate in tracking systolic arterialpressure changes over time. Thus, the use of pulse transit time as a surrogate measure of changes in systolic arterialpressure in children is a valid, non-invasive and inexpensive method with many potential applications. PMID:24605887

The aim of this research is to see the effect of intra-arterial infusion of leptin on blood pressure of salt loaded rabbits in vivo. Increased blood pressure was produced in rabbits by giving diets containing 8% sodium chloride for 5 weeks. Leptin in different concentrations was infused intra-arterially into rabbits fed on high salt diets and the response was compared in rabbits fed with low salt diets. High salt diets produced significant increase in blood pressure. In rabbits fed with low s...

Stability of myogenic tone in middle cerebral arteries (MCA) is essential for adequate control over penetration of pressure waves into the distal portion of the cerebral microcirculation. Because the increased pulse pressure observed in advanced aging is associated with cerebromicrovascular injury, the effect of aging on myogenic response of mouse MCAs was determined. Aging did not affect the myogenic constriction in response to static increases in pressure, whereas it significantly impaired pulsatile pressure-induced myogenic tone. Impaired myogenic adaptation of MCAs to pulsatile pressure may allow high pressure to penetrate the distal portion of the cerebral microcirculation, contributing to microvascular damage. PMID:25605292

A critical aspect of most cardiac catheterization procedures is the evaluation of myocardial function. At its simplest, this consists of a visual assessment of the left ventricular (LV) contractile pattern from the left ventriculogram, together with measurements of LV end-diastolicpressure. Measurements of pressures and cardiac output give important information about overall cardiac function, but may shed little light on the question as to whether dysfunction is due to abnormal systolic or diastolic myocardial performance. This chapter discusses some of the specific methods that can be used in the cardiac catheterization laboratory to examine myocardial performance in systole and diastole

In order to evaluate if elevation of the ischaemic limb above heart level is an alternative to the conventionally applied method with external counterpressure for estimation of skin perfusion pressure, femoral and popliteal arterypressures were measured directly in eight patients with occlusion of the superficial femoral artery. The measurements were done in the horizontal position and during elevation of the calf above heart level. During elevation relative blood flow, measured by arterio-venous oxygen saturation differences, decreased compared with the horizontal position. In contrast the popliteal arterialpressure decreased only by 20% of the value expected from the degree of elevation of the calf above the level of the heart. Thus, it could be calculated that calf vascular resistance increased two- to three-fold on average during elevation. Four patients were reexamined with the venous pressure kept at 10 mmHg during elevation. In these patients, the increase in vascular resistance was significantly less compared with the situation in which venous pressure was 0 mmHg during elevation. The arterialpressure still did not decrease. It is concluded that perfusion pressure in the ischaemic lower extremity cannot be determined non-invasively by elevation of the extremity, probably due to collapse of segments of the vascular bed increasing the vascular resistance considerably.

Caveolae are omega-shaped plasma membrane micro-domains that are abundant in cells of the vascular system. Formation of caveolae depends on caveolin-1 and cavin-1 and lack of either protein leads to loss of caveolae. Mice with caveolin-1 deficiency have dysfunctional blood vessels, but whether absence of cavin-1 similarly leads to vascular dysfunction is not known. Here we addressed this hypothesis using small mesenteric arteries from cavin-1-deficient mice. Cavin-1-reporter staining was intense in mesenteric arteries, brain arterioles and elsewhere in the vascular system, with positive staining of both endothelial and smooth muscle cells. Arterial expression of cavin-1, -2 and -3 was reduced in knockout (KO) arteries as was expression of caveolin-1, -2 and -3. Caveolae were absent in the endothelial and smooth muscle layers of small mesenteric arteries as determined by electron microscopy. Arginase, a negative regulator of nitric oxide production, was elevated in cavin-1 deficient arteries as was contraction in response to the ?1-adrenergic agonist cirazoline. Detailed assessment of vascular dimensions revealed increased media thickness and reduced distensibility, arguing that enhanced contraction was due to increased muscle mass. Contrasting with increased ?1-adrenergic contraction, myogenic tone was essentially absent and this appeared to be due in part to increased nitric oxide production. Vasomotion was less frequent in the knock-out vessels. In keeping with the opposing influences on arterial resistance of increased agonist-induced contractility and reduced myogenic tone, arterial blood pressure was unchanged in vivo. We conclude that deficiency of cavin-1 affects the function of small arteries, but that opposing influences on arterial resistance balance each other such that systemic blood pressure in unstressed mice is well maintained. PMID:24658465

We have tested the efficacy of a new long-acting preparation of pinacidil, an arterial vasodilator, using continuous intra-arterial ambulatory blood pressure recording. An acute dose produced a measurable effect lasting for 12 h. The duration of this effect was less during chronic twice daily drug administration. Side effects were common, causing two out of nine patients to withdraw from the study. Tilt testing produced no postural hypotension and there was no evidence of rebound hypertension...

Introduction: There are several potential explanations for the development of PH in patients with stable hemodialysis patients. Hormonal and metabolic derangement associated with end-stage renal failure might lead to pulmonary arterial vasoconstriction and an increase of the pulmonary vascular resistance. The aim of this study was to consider the association of pulmonary arterypressure (PAP) with serum parathormone in end-stage renal disease (ESRD) patients under regular hemodialysis treatme...

The pulmonary arterypressure (PAP) changes were studied using Doppler echocardiography in preterm infants treated with an artificial surfactant (Exosurf) during the acute phase of respiratory distress syndrome (RDS). The ratio of pulmonary artery acceleration time to the right ventricular ejection time (AT:RVET), measured from the Doppler wave form, was determined in 38 infants before the first dose of Exosurf, at one and six hours after the first dose, immediately before the second dose of ...

BACKGROUND: Dilatation of cranial vessels has been proposed as a part of the cascade that initiates an episode of migraine. This is based on the observation that intravenous administration of several substances with vasodilator properties can trigger migraine-like symptoms in migraineurs. METHODS: We used in vitro myography of human cerebral arteries and in vitro pressurized arteriography of rat middle cerebral artery (MCA) to evaluate the vasomotor responses of cerebral arteries to increasing concentrations of vasoactive substances used to elicit migraine-like attacks. RESULTS: All substances except carbachol induced a strong vasodilatory response when applied to the abluminal side of a rat MCA but negligible response when applied to the luminal side. Luminal carbachol gave a strong dilatory response but a weak response at the abluminal side. The prostaglandins PGE(2) and epoprostenol constricted the rat MCA while human cerebral arteries relaxed. The pEC(50) of carbachol, histamine, epoprostenol, VIP and sildenafil differed significantly between cerebral arteries from man and rat. The differences in pEC(50) for SNP, ?CGRP, PACAP-27 and PACAP-38 were not significant between the species. PGE(2) had no noticeable effect on human arteries in vitro. CONCLUSION: All tested substances with the exception of VIP and carbachol have been found to elicit migraine-like attacks in migraineurs. Since these two agents have vasodilatory effects in humans, it suggests that vasodilatation is not the only reason for eliciting a migraine-like attack in migraineurs. In addition, there are significant species differences that show the importance of performing experiments in human vessels.

With the publication in 1972 of a large computer model of circulatory control, Guyton and colleagues challenged the then prevailing views on how blood pressure and cardiac output were controlled. At that time, it was widely accepted that the heart controlled cardiac output and that peripheral resistance controlled arterial blood pressure. By incorporating the empirically demonstrated concepts of blood flow autoregulation and the pressure–natriuresis relationship into their mathematical mode...

Utilizing the formulation of so-called 'small deformations superimposed on a large initial deformation' the incremental pressure modulus of a ventricle in diastole is studied and the explicit expression of it is obtained as a function of intraventricular pressure. In the analysis the ventricular wall material is assumed to be homogeneous, incompressible, isotropic and the stress-strain relation is exponential. The numerical results for a dog left ventricle indicate that above a critical value of inner pressure the incremental pressure modulus increases with increasing intra-ventricular pressure. Furthermore, the relationship between the stiffness and pressure is seen to be curvilinear (particularly for low pressure level), but for large values of inner pressure the behavior of the curve may be approximated by a set of straight lines. PMID:6490674

We estimated total arterial compliance (C) in eight anesthetized mongrel dogs with (i) the area method (AM), (ii) the pulse pressure method (PPM), and (iii) the stroke volume-to-pulse pressure ratio (SV/PP). Average compliance was C(AM)=1.1+/-0.73 ml mm Hg(-1) using AM; C(PPM)=0.60+/-0.31 ml mm Hg(-1) using PPM and C(SV/PP)=0.87+/-0.49 ml mm Hg(-1) using SV/PP. Mean aortic pressure was 64+/-23 mm Hg. The overall agreement between C(AM) and C(PPM) was relatively poor (C(AM)=0.15+/-1.61 C(PPM); r2=0.48), with a consistent overestimation of the area method with respect to the pulse pressure method. There was a significant correlation (r=-0.78) between the relative difference between PPM and AM, and the modulus of the first harmonic of the wave reflection coefficient [gamma] which was low in our dog population (0.37+/-0.18). SV/PP overestimated PPM, but both methods were highly correlated (C(SV/PP)=0.06+/-1.60C(PPM); r2=0.97). C(SV/PP) and C(AM) were similar only for [gamma]>0.4. The effect of isolated changes of [gamma] on PPM, AM, and SV/PP was studied using the linear wave separation technique. The area method appeared very sensitive to the wave reflection intensity. For low reflection coefficients, the diastolic wave profile was flattened and compliance was overestimated. PPM and SV/PP were relatively independent of [gamma] and remained even applicable for [gamma]=0. We believe that the pulse pressure method is the most consistent method for the estimation of total arterial compliance in hemodynamic conditions characterized by a low wave reflection intensity. PMID:10468232

Background: The myocardium is generally injured in the case of reperfusion injury and arterial damage is caused by hypertension. In reference to these statements, the present study was focused. Cardiac glycosides were said to have protective effects against myocardial infarction and hypertension. Strophanthus hispidus was thus incorporated in the study. Objective: The prime objective of the study was to investigate the protective effects of Strophanthus hispidus against ischemia-reperfusion myocardial Infarction and renal artery occluded hypertension in rats. Materials and Methods: The animal model adopted was surgically-induced myocardial ischemia, performed by means of left anterior descending coronary artery occlusion (LAD) for 30 min followed by reperfusion for another 4 h. Infarct size was assessed by using the staining agent TTC (2,3,5-triphenyl tetrazolium chloride). Hypertension was induced by clamping the renal artery with renal bulldog clamp for 4 h. Results: The study was fruitful by the effect of Strophanthus hispidus on infarction size, which got reduced to 27.2 ± 0.5and 20.0 ± 0.2 by 500 mg/Kg and 1000 mg/Kg ethanolic extracts which was remarkably significant when compared with that of the control group 52.8 ± 4.6. The plant extract did reduce heart rate at various time intervals. There was also a protective effect in the case of mean arterial blood pressure were the 500 mg/Kg and 1000 mg/Kg of the plant extract did reduce the hypertension after 60 minutes was 60.0 ± 4.80 and 50.50 ± 6.80. Conclusion: The results suggest that 500 mg/Kg and 100 mg/Kg ethanolic extract of Strophanthus hispidus was found to possess significant cardiac protective and anti-hypertensive activity. PMID:25298674

The maintenance of arterialpressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pr...

Full Text Available Introduction: There are several potential explanations for the development of PH in patients with stable hemodialysis patients. Hormonal and metabolic derangement associated with end-stage renal failure might lead to pulmonary arterial vasoconstriction and an increase of the pulmonary vascular resistance. The aim of this study was to consider the association of pulmonary arterypressure (PAP with serum parathormone in end-stage renal disease (ESRD patients under regular hemodialysis treatment. Material and methods: This cross-sectional study was conducted on patients with end-stage renal disease undergoing maintenance hemodialysis treatment through an arteriovenous fistula which was created on the hand, and with acetate basis dialysate and polysulfone membranes. For all patients serum intact parathormone (iPTH was measured. For assessment of pulmonary arterypressure, all patients were subjected to two-dimensional and doppler echocardiographic studies that were done for the patients after their hemodialysis sessions. Results: The study comprised 102 patients (F=46, M=56 consisting of 73 non diabetic hemodialysis patients (F=33, M=40, and 29 diabetic hemodialysis patients (F=13, M=16. The duration of hemodialysis was 17.8±29 months. The mean ±SD of serum iPTH of total patients was 338±306 pg/ml. The mean ±SD of pulmonary artery systolic pressure (PAP was 41.5±12.6 mmHg. A significant positive correlation of PAP with the dosage (r=0.36, p=0.001 and duration of hemodialysis (r=0.35, p<0.001 was seen, also a significant positive correlation of pulmonary artery systolic pressure with serum intact parathormone (iPTH in hemodialysis patients was found. Conclusions: A significant positive correlation of serum intact parathormone with pulmonary arterypressure, which is a new aspect of uncontrolled secondary hyperparathyroidism implies the need for a better control of poorly controlled hyperparathyroidism disease in hemodialysis patients.

Wedge pressure of the occluded major cerebral artery (distal pressure beyond the occlusion) was measured to estimate the residual cerebral blood flow in thirteen patients with acute ischemic stroke. There existed the relationship that patients with higher wedge pressure tolerated longer ischemic insults than those with lower wedge pressure. Wedge pressure is measured with minimum time loss before starting thrombolytic therapy and may be a good indicator to estimate the brain tissue reversibil...

Ground studies indicate that spaceflight may diminish vascular contraction. To examine that possibility, vascular function was measured in spontaneously hypertensive rats immediately after an 18-day shuttle flight. Isolated mesenteric resistance arterial responses to cumulative additions of norepinephrine, acetylcholine, and sodium nitroprusside were measured using wire myography within 17 h of landing. After flight, maximal contraction to norepinephrine was attenuated (P vivarium control animals (P < 0.05). The results are consistent with data from ground studies and indicate that spaceflight causes both endothelial-dependent and endothelial-independent alterations in vascular function. The resulting decrement in vascular function may contribute to orthostatic intolerance after spaceflight.

The differences in simultaneous arterialpressure measurements from the radial and dorsalis pedis arteries were studied in anaesthetised adult patients in either the horizontal or reverse Trendelenburg position. Significantly higher pressures were measured from the dorsalis pedis artery than from the radial artery in both positions, even allowing for the hydrostatic effect on the dorsalis pedis arterialpressure in the non-horizontal group. If the dorsalis pedis artery is to be used to measure direct arterial blood pressure, we recommend that readings be compared with an arm sphygmomanometer to avoid potentially dangerous hypotension being missed. PMID:7618675

Aqueous outflow via the conventional outflow pathway is dependent on the pressure gradient between intraocular pressure (IOP) and episcleral venous pressure (EVP). Elevated IOP resulting from increased EVP is a well-known complication of arteriovenous fistulas, which are usually between the carotid artery and the cavernous sinus. Arteriovenous malformations usually occur spontaneously, after a trauma or from iatrogenic causes, and they manifest with findings of chemosis, dilatation of the conjunctival vessels, exophthalmos, and extraocular motility limitation. In this study, we present a case of elevated IOP due to facial arteriovenous malformations following a functional neck dissection surgery that caused intraocular pressure elevation. PMID:25349756

Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging

Full Text Available This prospective randomized study aims to evaluate and compare the effects of isoflurane, sevoflurane and desflurane (study drugs on left ventricular (LV diastolic function in patients with impaired LV relaxation due to ischemic heart disease using transesophageal Doppler echocardiography. After approval of the local ethics committee and informed consent, 45 patients scheduled for coronary artery bypass grafting surgery were enrolled in the study. Patients were selected by a preoperative Transthoracic Echocardiographic diagnosis of impaired relaxation or Grade 1 Diastolic Dysfunction. They randomly received fentanyl and midazolam anesthesia with 1 MAC of isoflurane (n=16, sevoflurane (n=14 or desflurane (n=15. Hemodynamic parameters and TEE derived ventricular diastolic relaxation indices before and after the study drug administration were compared. LV filling pressures were kept constant throughout the study period to exclude the effect of the loading conditions on diastolic function. Four patients in the sevoflurane group and three in the desflurane group were excluded from the study, after baseline TEE examination revealed normal diastolic filling pattern. All the three study drugs significantly reduced the systemic vascular resistance index with a significant increase in cardiac index. Mean arterialpressure was reduced by all the drugs, although the decrease was not statistically significant. Hemodynamic changes were comparable between all the three groups. In terms of LV relaxation indices, all three agents led to a significant improvement in diastolic function. Transmitral and Tissue Doppler E/A and Em/Am ratios improved significantly Transmitral and Tissue Doppler E/A and Em/Am ratios improved significantly accompanied by a significant decrease in deceleration time and isovolumetric relaxation time. The effect of all three agents on diastolic relaxation parameters was comparable. In conclusion , Isoflurane, sevoflurane and desflurane, do not appear to have a detrimental effect in patients with early diastolic dysfunction. On the contrary, these inhalational agents actually improve the LV relaxation. A significant reduction in afterload produced by these vapors can be a possible reason for these findings. The positive effect of these inhalational agents on LV relaxation can have a profound effect on the perioperative anesthetic management of patients with diastolic dysfunction.

Diastolic dysfunction is frequently seen after myocardial infarction and is characterized by a disproportionate increase in filling pressure during exercise to maintain stroke volume. We hypothesized that sildenafil would reduce filling pressure during exercise in patients with diastolic dysfunction after myocardial infarction.

Full Text Available Blood pressure checking and its theoretical knowledge are crucial to obtain reliable data in clinical examination. Although it is considered a simple technique to be learned and applied, it is not fully dealt with at physiotherapy university courses. Therefore, a wide range of mistakes and misinterpretations are likely to threaten treatment quality. This work aims to evaluate the theory background of physiotherapists for blood pressure measurement. From June to October 2002, 55 physiotherapists answered a 20- question multiple-choice questionnaire on general knowledge related to concepts, anatomy and physiology, suitable equipment, indirect measurement, blood pressure values, mistakes and misinterpretation factors related to blood pressure measurement. The results disclose faulty theory concepts in the sample studied, indicating the need of deeper approach to this complex theme during course and ongoing updating of professionals.

Full Text Available Aim. To compare antihypertensive effect of ramipril monotherapy at morning and evening taking.Material and methods. 22 patients (10 men, 12 women; aged 62,1±1,9 y.o. with arterial hypertension of 1-2 stage were involved into the open randomized crossover study. Patients were randomized into 2 groups depending on ramipril taking time (morning or evening. Ambulatory blood pressure (BP monitoring (ABPM was performed. Patients of both groups were comparable in basic clinical characteristics and initial ABPM indices. Analysis of peak and phase characteristics of 24 hour BP profile was used as well as standard evaluation. Treatment duration was 3 weeks. Ramipril dose titration was made in 1,5 weeks. The average daily dose of ramipril was 6,1 mg in the morning taking, and 5,0 mg in the evening taking.Results. 20 patients finished study completely. 24 hour initial level of systolic (SBP and diastolic BP (DBP was 141,5±1,6/85,3±1,1 mm Hg. After ramipril monotherapy with evening taking BP reduced to 132,6±1,6/79,8±1,1 mm Hg (p<0,001 and with morning taking – to 131,8±1,6/79,2±1,1 mm Hg (p<0,001. Evening ramipril taking led to significant improvement of 24 hour BP profile. Night SBP/DBP reduction became deeper from 7,7±1,2/11,5±1,3% to 12,5±1,2/19,1±1,3 % (p<0,01. Morning taking did not have significant influence on these indices. Ramipril did not result in clinically significant hypotension including night one.Conclusion. Evening ramipril taking is effective and safe. It can be recommended to patients with insufficient night BP dipping (non dippers.

Thirty patients with essential hypertension participated in a double blind crossover trial in which they were randomly allocated to treatment with either once daily slow release metoprolol (200 mg) with placebo or once daily slow release metoprolol (200 mg) with chlorthalidone (25 mg). Ambulatory intra-arterial blood pressure was recorded continuously for 24-48 hours before treatment and two months after each change in regimen. The response of blood pressure and pulse rate to a standard exerc...

Previous work has shown remarkable differences in the pressure-flow relations of the pulmonary circulation between birds and mammals. For example several studies suggest that the avian pulmonary blood vessels behave like rigid tubes, very different from the situation in mammalian lung. We therefore speculated that birds would develop high pulmonary arterypressures when the cardiac output was substantially increased during heavy exercise, for example during flight. However because of the tech...

A new method for analyzing arterial blood pressure is presented in this article. The technique is based on the scattering transform and consists in solving the spectral problem associated to a one-dimensional Schrödinger operator with a potential depending linearly upon the pressure. This potential is then expressed with the discrete spectrum which includes negative eigenvalues and corresponds to the interacting components of an N-soliton. The approach is similar to a nonlinear Fourier transf...

A new method for analyzing arterial blood pressure is presented in this report. The technique is based on the scattering transform and consists in solving the spectral problem associated to a one-dimensional Schr\\"odinger operator with a potential depending linearly upon the pressure. This potential is then expressed with the discrete spectrum which includes negative eigenvalues and corresponds to the interacting components of an N-soliton. The approach is similar to a nonli...

A clinical comparison of the effects on pulmonary arterialpressure induced by contrast media with various osmolalities, iohexol 140 mg I/ml (300 mosm/kg H2O), iohexol 300 mg I/ml (690 mosm/kg H2O), and diatrizoate 292 mg I/ml (1480 mosm/kg H2O) following selective pulmonary angiography was made in 12 patients with normal pulmonary arterialpressure. A double-blind crossover study was performed and the contrast media were administered in random order. The pulmonary arterialpressure was recorded continuously before, during, and for 3 min after the injection. The effect of iohexol 140 on the pulmonary arterialpressure was significantly less marked than that of diatrizoate 292, whereas no statistical significance was shown between iohexol 140 and iohexol 300. These results indicate that iso-osmolar contrast medium (iohexol 140), as well as iohexol 300, would be better tolerated than diatrizoate 292, and is therefore a safer contrast medium for selective pulmonary angiography. (orig.)

Heart failure has reached epidemic proportions, and diastolic heart failure or heart failure with preserved ejection fraction (HFpEF) constitutes about 50% of all heart failure admissions. Long-term prognosis of both reduced ejection fraction heart failure and HFpEF are similarly dismal. No pharmacologic agent has been developed that actually treats or repairs the physiologic deficit(s) responsible for HFpEF. Because the physiology of diastole is both subtle and counterintuitive, its role in heart failure has received insufficient attention. In this review, the focus is on the physiology of diastole in heart failure, the dominant physiologic laws that govern the process in all hearts, how all hearts work as a suction pump, and, therefore, the elucidation and characterization of what actually is meant by "diastolic function". The intent is for the reader to understand what diastolic function actually is, what it is not, and how to measure it. Proper measurement of diastolic function requires one to go beyond the usual E/A, E/E', etc. phenomenological metrics and employ more rigorous causality (mathematical modeling) based parameters of diastolic function. The method simultaneously provides new physiologic insight into the meaning of in vivo "equilibrium volume" of the left ventricle (LV), longitudinal versus transverse volume accommodation of the chamber, diastatic "ringing" of the mitral annulus, and the mechanism of L-wave generation, as well as availability of a load-independent index of diastolic function (LIIDF). One important consequence of understanding what diastolic function is, is the recognition that all that current therapies can do is basically alter the load, rather than actually "repair" the functional components (chamber stiffness, chamber relaxation). If beneficial (biological/structural/metabolic) remodeling due to therapy does manifest ultimately as improved diastolic function, it is due to resumption of normal physiology (as in alleviation of ischemia) or activation of compensatory pathways already devised by evolution. In summary, meaningful quantitative characterization of diastolic function in any clinical setting, including heart failure, requires metrics based on physiologic mechanisms that quantify the suction pump attribute of the heart. This requires advancing beyond phenomenological global indexes such as E/A, E/E', Vp, etc. and employing causality (mathematical modeling) based parameters of diastolic function easily obtained via the parametrized diastolic function (PDF) formalism. PMID:25922587

Heart failure has reached epidemic proportions, and diastolic heart failure or heart failure with preserved ejection fraction (HFpEF) constitutes about 50% of all heart failure admissions. Long-term prognosis of both reduced ejection fraction heart failure and HFpEF are similarly dismal. No pharmacologic agent has been developed that actually treats or repairs the physiologic deficit(s) responsible for HFpEF. Because the physiology of diastole is both subtle and counterintuitive, its role in heart failure has received insufficient attention. In this review, the focus is on the physiology of diastole in heart failure, the dominant physiologic laws that govern the process in all hearts, how all hearts work as a suction pump, and, therefore, the elucidation and characterization of what actually is meant by “diastolic function”. The intent is for the reader to understand what diastolic function actually is, what it is not, and how to measure it. Proper measurement of diastolic function requires one to go beyond the usual E/A, E/E?, etc. phenomenological metrics and employ more rigorous causality (mathematical modeling) based parameters of diastolic function. The method simultaneously provides new physiologic insight into the meaning of in vivo “equilibrium volume” of the left ventricle (LV), longitudinal versus transverse volume accommodation of the chamber, diastatic “ringing” of the mitral annulus, and the mechanism of L-wave generation, as well as availability of a load-independent index of diastolic function (LIIDF). One important consequence of understanding what diastolic function is, is the recognition that all that current therapies can do is basically alter the load, rather than actually “repair” the functional components (chamber stiffness, chamber relaxation). If beneficial (biological/structural/metabolic) remodeling due to therapy does manifest ultimately as improved diastolic function, it is due to resumption of normal physiology (as in alleviation of ischemia) or activation of compensatory pathways already devised by evolution. In summary, meaningful quantitative characterization of diastolic function in any clinical setting, including heart failure, requires metrics based on physiologic mechanisms that quantify the suction pump attribute of the heart. This requires advancing beyond phenomenological global indexes such as E/A, E/E?, Vp, etc. and employing causality (mathematical modeling) based parameters of diastolic function easily obtained via the parametrized diastolic function (PDF) formalism. PMID:25922587

Full Text Available Since antiquity, the human arterial pulse represents an important parameter in the clinical assessment. Besides being routinely assessed in the medical practice, such pulse is not observed in its completeness yet, once many of the data obtained through it cannot be evaluated using conventional methods. Taking into account such methods, the measurement of arterial blood pressure using sphygmomanometry, although broadly widespread in the assessment and follow-up of patients who require accompaniment of their cardiovascular status, is not able to properly guide about parameters related to the central hemodynamic status, the latter most strongly associated with cardiovascular risk. Such incapability is due to the centrifugal augmentation of the pressures taken at different points of the arterial bed, based on the properties of the closed arterial system through which the blood flow travels. In this context, methodologies capable of assessing central parameters estimated using the pulse wave analysis, such as applanation tonometry, represent a promising adjuvant for evaluating patients with cardiovascular diseases, by providing detailed information concerning hemodynamic parameters otherwise inaccessible. In this scenario, the present review focuses on the applanation tonometry and its assessment on the radial artery, highlighting the importance of this method in the cardiovascular assessment, as well as its relevance in the clinical practice, when determining parameters peripherally obtained capable of estimating the central hemodynamic status.

Invasive blood pressure measurement (IBP) using peripheral arteries is a commonly used technique in equine anaesthesia, although the accuracy has not been demonstrated. Non-invasive blood pressure monitoring (NIBP) may be indicated for field anesthesia, short procedures and foal anaesthesia. In the present report, the agreement of various IBP and NIBP measuring sites compared to carotid arterypressure was tested in anaesthetised experimental ponies. Six ponies were anaesthetised in lateral r...

Abstract Background In patients with idiopathic normal pressure hydrocephalus (iNPH) responding to shunt surgery, we have consistently found elevated intracranial pressure (ICP) wave amplitudes during diagnostic ICP monitoring prior to surgery. It remains unknown why ICP wave amplitudes are increased in these patients. Since iNPH is accompanied by a high incidence of vascular co-morbidity, a possible explanation is that there is reduced vascular compliance accompanied by elevated arterial blo...

An inflatable small plastic bag including a photo sensor was constructed for measurement of skin perfusion pressure avoiding the rim of the photo sensor over bony and tendineous surfaces of the tibia below the knee, at the ankle, and on the dorsal forefoot. Compression was obtained using a conical blood pressure cuff with continuous decrease from suprasystolic arm pressure. The validity of skin perfusion pressure with the new device was compared to that of isotope washout below the knee in normal subjects and in patients with an ischemic forefoot with acceptable agreement. The method had a high reproducibility within and between days in normal subjects. Compared to systolic arterialpressure measured using a strain gauge with a cuff on the ankle in normal subjects and patients with intermittent claudication the new device showed blood pressure in the skin closer to the diastolicpressure. The new pressure device thus had acceptable validity and reproducibility for estimation of the skin perfusion pressure andcan be used on bony and tendineous sites on the lower limb in regions where critical wound healing is frequent, e.g. ankle and forefoot.

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detecheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse oximeters showed gradual decrease of saturations during induced hypoperfusion which demonstrate the direct relation between blood volumes (PPG amplitudes), arterial vessel stenosis and blood oxygen saturation. The custom made pulse oximeter was found to be more sensitive to SpO2 changes than the commercial pulse oximeter especially at high occluding pressures

There are no clinical studies on the effects of catheter-based radiofrequency renal denervation (RDN) on renal artery structure using 64-detector computed tomography (CT). A total of 39 patients with resistant hypertension received RDN and 38 patients received drug treatment. Mean systolic pressure and diastolicpressure in the RDN group decreased after 1, 3, 6, and 12 months of procedure (P

Full Text Available The anatomical differences between the pulmonary and systemic arterial system are the main cause of the difference in distribution of compliance. In the pulmonary arterial system compliance is distributed over the entire arterial system, and stands at the basis of the constancy of the RC-time. This distribution depends on the number of peripheral vessels, which is ?8–10 times more in the pulmonary system than the systemic tree. In the systemic arterial tree the compliance is mainly located in the aorta (80% of total compliance in thoracic-abdominal aorta. The constant RC-time in the pulmonary bed results in proportionality of systolic and diastolicpressure with mean pressure and, in turn, in the constant ratio of oscillatory and mean power.

This study demonstrated the concept of using speed modulation in a continuous-flow total artificial heart (CFTAH) to shape arterialpressure waveforms and to adjust pressure pulsatility. A programmable function generator was used to determine the optimum pulsatile speed profile. Three speed profiles (sinusoidal, rectangular, and optimized [a profile optimized for generation of a physiologic arterialpressure waveform]) were evaluated using the CFTAH mock circulatory loop. Hemodynamic paramete...

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO{sub 2}) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO{sub 2}) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO{sub 2} sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse oximeters showed gradual decrease of saturations during induced hypoperfusion which demonstrate the direct relation between blood volumes (PPG amplitudes), arterial vessel stenosis and blood oxygen saturation. The custom made pulse oximeter was found to be more sensitive to SpO{sub 2} changes than the commercial pulse oximeter especially at high occluding pressures.

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse oximeters showed gradual decrease of saturations during induced hypoperfusion which demonstrate the direct relation between blood volumes (PPG amplitudes), arterial vessel stenosis and blood oxygen saturation. The custom made pulse oximeter was found to be more sensitive to SpO2 changes than the commercial pulse oximeter especially at high occluding pressures.

BACKGROUND: The tallest animal on Earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal hemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. METHODS: Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural, and histological characteristics of vascular and renal tissues were determined. RESULTS: GFR averaged 342±99 ml min(-1) and ERPF 1252±305 ml min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39±2 mmHg and renal venous pressure 32±4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12±2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6±0.5 mIU/l and 9.1±1.5 pg/ml, respectively. CONCLUSION: In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP. This article is protected by copyright. All rights reserved.

1. Peroneal muscle sympathetic nerve activity (MSA), finger blood pressure and cardiac intervals were recorded at rest in 60 healthy subjects, aged 18-71 years. Arterial baroreflex control of MSA was analysed by relating each spontaneous sympathetic burst to the diastolic blood pressure and the cardiac interval of the heart beat during which the burst was generated. The results were expressed as blood pressure/cardiac interval threshold for occurrence of bursts, and as baroreflex sensitivity ...

Presently, the ambulatory (A) blood (B) pressure (P) monitoring (M) is mainly used for diagnosing arterial hypertension (AH) in some special clinical conditions in which the causal sphygmomanometry appears not to be enough exhaustive. However, it must be pointed out that the actual approach to ABPM is almost simplistic, only consisting in a biometric analysis of discrete raw temporal values for systolic (S) and diastolic (D) BP and heart rate (HR). It must be stressed that BP and HR are hemodynamic variables characterized by a well established circadian rhythm (C) in their 24-h physiological values. Therefore, an appropriate chronobiometric approach, via Single Cosinor method, can improve the diagnostic value, its optimal oscillatory curve reducing all the biometric information to three parameters, i.e., MESOR (M, mean level of oscillation), Amplitude (A, extent of oscillation from M) and Acrophase (phi, timing of A with respect to local midnight). Accordingly, one can detect whether the BP CR is still manifest, as it is in essential hypertension (EH), or altered , as it is in secondary hypertension (SH). Therefore, by using the discriminant analysis for the three multivariate parameters, M, A, phi, of the BP cosine curve, one can statistically predict whether a new monitored hypertensive patient has a significant probability to be affected by EH or SH. Interestingly, by applying a further chronobiometric integration analysis, i.e., the Cosint analysis, it is possible to estimate the area under the BP oscillatory curve, for calculating the overall, diurnal, nocturnal, hourly pressure load (Baric Impact, BI) in terms respectively of mm2 Hg/24-h, mm2 Hg/16-h, mm2Hg/8-h, mm2 Hg/1-h. By comparing the overall BI of the new monitored hypertensive patient to its upper reference limit, one can estimate how much is the Baric Excess (Hyperbaric Impact, HI) caused by the personal hypertensive regimen. Finally, by using the chaos method of fractal interpolation to BP 24-h values, it is possible to establish whether or not the monitored hypertensive subject is presumably at risk of unpredictable high BP values (presumable risk of hypertensive crisis). PMID:19169597

Full Text Available Objective: Examine pulmonary artery systolic pressure (PASP response to exercise in isolated borderline and mild to moderate pulmonary arterial hypertension (PAH.Methods: Doppler stress echocardiography was performed in 32 healthy volunteers with resting PASP of 29 mm Hg or less, 39 with resting PASP between 30 and 40 mm Hg, and 7 with resting PASP between 41 and less than 60 mm Hg. All subjects had otherwise normal echocardiograms.Results: Rate of increase in PASP with exercise was positively associated with resting PASP (P 0.001, increased age (P 0.001, and estrogen use among women (P = 0.001. On multivariate analysis, PASP slope was independently related (P = 0.03 to resting PASP and inversely associated with exercise time (P 0.001.Conclusions: Patients with borderline and mild to moderate resting PAH have an exaggerated PASP response to exercise. PASP slope is a strong independent predictor of exercise time. Outcome studies are needed to determine the prognostic significance of this finding.

A self-tuning controller was implemented for the automated infusion of sodium nitroprusside to lower mean arterialpressure in anesthetized dogs. The system incorporated a recursive least-squares parameter identifier and a modified minimum-variance controller. The onset delay was estimated on-line, the performance criterion included the cost of control, and requested step-changes were automatically translated into five successive smaller steps to reduce overshoot. The performance of the system in lowering mean arterialpressure was quantitatively compared with that of a well-trained anesthesiologist. In 10 runs in four animals, the automated system performed as well as the physician who devoted 100% of his attention to the task. Since the stability of the self-tuning controller cannot be guaranteed, such a system should be operated only in the presence of appropriate supervisory algorithms. PMID:4073623

Heart failure is one of the most important medical problems facing societies in developed economies and its prevalence is predicted to rise inexorably in the next few decades as longevity increases. Worsening heart failure leading to hospitalization is associated with a poor prognosis and imposes a substantial burden on health care resources and budgets. Interventions that can stabilize patients should reduce the need for hospitalization and improve prognosis. This might be facilitated by frequent self-monitoring of clinical and physiological variables by patients themselves at home. Rising pulmonary arterypressure is an early sign of cardiac decompensation that may be more sensitive than conventional methods of patient assessment and thus allow early adjustment of medical therapy to avoid hospitalizations and improve patient outcomes. Remote monitoring of pulmonary arterypressure is now possible using devices that can be implanted percutaneously. This innovative technology could become a routine part of the management of heart failure in the next few decades. PMID:24984847

In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterialpressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred.

These students, as representative of french population, were examined in 1983. Right humeral arterial blood pressure was measured three times on dorsal decubitus with a mercury manometer by a medical doctor. People with a systolic arterialpressure greater than or equal to 150 mmHg and/or diastolicarterialpressure greater than or equal to 90, were considered as hypertensive. These hypertensive people came then for a new complete examination, six months later. A witness group, drawn by lot, were examined in the same conditions. Systolic, diastolic and mild arterial blood pressures (in mmHg) were for: (table; see text) Prevalence of hypertension is 2.2 p. 100 (46) for girls and 11.9 p. 100 (184) for boys. The most important difference between high blood pressure people and normal blood pressure people lies in morphological characters. (Table: see text). Sport activities, coffee and diet concerning sodium are identical in the two groups. High blood pressure people smoke less than normal blood pressure people. Previous history of hypertension are more frequent in high blood pressure people than normal blood pressure people. Upright posture induce modification in pressure on high blood pressure people. Meanwhile, stress induced by mental arithmetic, does not bring more elevation pressure about high blood pressure people than normal blood pressure people. Six months later: 58 p. 100 of high blood pressure group have still a high blood pressure, 26 p. 100 have a borderline blood pressure (systolic greater than or equal to 140, diastolic greater than or equal to 85).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3938233

Full Text Available Abstract Background Recently, a cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been validated. A further application is the assessment of Second Heart Sound (S2 amplitude variations at increasing heart rates. The aim of this study was to assess the relationship between second heart sound amplitude variations at increasing heart rates and hemodynamic changes. Methods The transcutaneous force sensor was positioned in the precordial region in 146 consecutive patients referred for exercise (n = 99, dipyridamole (n = 41, or pacing stress (n = 6. The curve of S2 peak amplitude variation as a function of heart rate was computed as the increment with respect to the resting value. Results A consistent S2 signal was obtained in all patients. Baseline S2 was 7.2 ± 3.3 mg, increasing to 12.7 ± 7.7 mg at peak stress. S2 percentage increase was + 133 ± 104% in the 99 exercise, + 2 ± 22% in the 41 dipyridamole, and + 31 ± 27% in the 6 pacing patients (p Conclusion S2 recording quantitatively documents systemic pressure changes.

Pulmonary hypertension (PH) is associated with aberrant vascular remodeling and right ventricular (RV) dysfunction that contribute to early mortality. Large animal models that recapitulate human PH are essential for mechanistic studies and evaluating novel therapies; however, these models are not readily accessible to the field owing to the need for advanced surgical techniques or hypoxia. In this study, we present a novel swine model that develops cardiopulmonary hemodynamics and structural changes characteristic of chronic PH. This percutaneous model was created in swine (n=6) by combining distal embolization of dextran beads with selective coiling of the lobar pulmonary arteries (2 procedures per lung over 4 weeks). As controls, findings from this model were compared with those from a standard weekly distal embolization model (n=6) and sham animals (n=4). Survival with the combined embolization model was 100%. At 8 weeks after the index procedure, combined embolization procedure animals had increased mean pulmonary arterypressure (mPA) and pulmonary vascular resistance (PVR) compared to the controls with no effect on left heart or systemic pressures. RV remodeling and RV dysfunction were also present with a decrease in the RV ejection fraction, increase in the myocardial performance index, impaired longitudinal function, as well as cardiomyocyte hypertrophy, and interstitial fibrosis, which were not present in the controls. Pulmonary vascular remodeling occurred in both embolization models, although only the combination embolization model had a decrease in pulmonary capacitance. Taken together, these cardiopulmonary hemodynamic and structural findings identify the novel combination embolization swine model as a valuable tool for future studies of chronic PH. PMID:25923775

Full Text Available Objective: To assess the effects of percutaneous transluminal angioplasty and stenting (PTRA/S on arterial blood pressure and renal function.Methods: A retrospective chart review of patients undergoing PTRA/S at our institution between December 2003 and September 2006 was done. Follow-up data were derived from hospital records. Estimated glomerular filtration rate (EGFR was used as the marker of renal function. To evaluate the pre- and post-procedure values in individual patients the paired t test and Wilcoxon signed-rank tests were used.Results: Thirty-six patients (16 women, 30 men; mean age 59±15 years, range: 25-83 years underwent 43 PTRA/S interventions at our institution. The mean duration of follow-up was 9.3±8.6 (range 2-28 months. We observed no significant change in EGFR from pre-procedure to that obtained at follow-up (71.4±40.2 mL/min vs.73.3±39.0 mL/min; p=0.483. Mean arterial blood pressure (MABP, however, was reduced significantly: pre-procedure MABP-123±22 mmHg; post-procedure follow-up value of 101±14 mmHg (p <0.001. The mean number of antihypertensive medications used at the time of intervention was 2.1±1.0 (range: 0-4, whereas at follow-up, this number had decreased to 1.3±1.0 (range: 0-4; p<0.001. In patients with renal impairment (EGFR ?59 mL/min, 41% showed improvement, 29% showed no change and 29% demonstrated deterioration in EGFR. Conclusion: PTRA/S may preserve renal function, especially in patients with pre-procedural impaired renal function.

Giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists for centuries. The authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright standing position, and determined the ratio between tunica media and lumen areas along the length of the femoral/tibial arteries in the hindleg. Volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. Immunohistological staining with S100 was used to examine the innervation. The pressure increase in the artery and vein along the foreleg was not significantly different from what was expected on basis of gravity. The area of the arterial lumen in the hindleg decreased towards the hoof from 11.2 ± 4.2 to 0.6 ± 0.5 mm(2) (n = 10, P = 0.001), but most of this narrowing occurred within 2-4 cm immediately below the knee. This abrupt narrowing was associated with a marked increase in media to lumen area ratio (from 1.2 ± 0.5 to 7.8 ± 2.5; P = 0.001), and a decrease in mean volume fraction of elastin from 38 ± 6% proximal to the narrowing to 5.8 ± 1.1% distally (P = 0.001). The narrowing had a six-fold higher innervation density than the immediate distal and proximal regions. The sudden narrowing was also observed in the hind legs of neonates, indicating that it does not develop as an adaptation to the high transmural pressure in the standing giraffe. More likely it represents a preadaptation to the high pressures experienced by adult giraffes.

Variability in arterialpressure and cerebral blood flow has traditionally been interpreted as a marker of cardiovascular decompensation, and has been associated with negative clinical outcomes across varying time scales, from impending orthostatic syncope to an increased risk of stroke. Emerging evidence, however, suggests that increased hemodynamic variability may, in fact, be protective in the face of acute challenges to perfusion, including significant central hypovolemia and hypotension...

Full Text Available AIM: To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. PATIENTS AND METHODS: We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. RESULTS: After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9?2 times. CONCLUSION: The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

Full Text Available The aim of the investigation is to study the peculiarities of pulmonary circulatory dynamics in patients with bronchial asthma, develop and apply an analytical model of correlation between systolic pressure in pulmonary artery and respiratory function (RF values. Materials and Methods. 112 patients with severe bronchial asthma (BA were examined. Physical examination, RF and echo Doppler cardiography were performed in all patients. Results. The presence of obstructive syndrome was confirmed when performing RF investigation in patients with severe BA. Severe pulmonary hypertension was also revealed in patients with severe BA. The pressure in pulmonary artery was increasing in bronchial obstruction progression and the reduction of forced expiratory volume per second (FEV1 that was represented by negative significant correlation dependence between the given parameters (r=–0.48; ?=0.005. There was developed an analytical model of dependence between FEV1 and the level of systolic pressure in pulmonary artery based on linear regression analysis. The model enables to assess approximately the main parameters of pulmonary circulatory dynamics in BA patients in clinical practice. Conclusion. Pulmonary hypertension revealed in 53.2% of BA patients has moderate functional character. One of the determining factors of pulmonary hypertension in bronchial asthma is bronchial obstruction. There is strong correlation and analytical interrelation between RF and pulmonary circulatory dynamics values.

Prepump arterialpressure (PreAP) is monitored to avoid generating excessive negative pressure. The National Kidney Foundation K/DOQI clinical practice guidelines for vascular access recommend that PreAP should not fall below -250?mm?Hg because excessive negative PreAP can lead to a decrease in the delivery of blood flow, inadequate dialysis, and hemolysis. Nonetheless, these recommendations are consistently disregarded in clinical practice and pressure sensors are often removed from the dialysis circuit. Thus far, delivered blood flow has been reported to decrease at values more negative than -150?mm?Hg of PreAP. These values have been analyzed by an ultrasonic flowmeter and not directly measured. Furthermore, no known group has evaluated whether PreAP-induced hemolysis occurs at a particular threshold. Therefore, the aim of this study was to clarify the importance of PreAP in the prediction of inadequate dialysis and hemolysis. By using different diameter needles, human blood samples from healthy volunteers were circulated in a closed dialysis circuit. The relationship between PreAP and delivered blood flow or PreAP and hemolysis was investigated. We also investigated the optimal value for PreAP using several empirical monitoring methods, such as a pressure pillow. Our investigation indicated that PreAP is a critical factor in the determination of delivered blood flow and hemolysis, both of which occured at pressure values more negative than -150?mm?Hg. With the exception of direct pressure monitoring, commonly used monitoring methods for PreAP were determined to be ineffective. We propose that the use of a vacuum monitor would permit regular measurement of PreAP. PMID:25940509

While occupational injury is associated with numerous individual and work-related risk factors, including long working hours and short sleep duration, the complex mechanisms causing such injuries are not yet fully understood. The relationship between the infrasound pressures of the tympanic membrane [ear canal pressure (ECP)], detected using an earplug embedded with a low-frequency microphone, and the carotid artery [carotid arterypressure (CAP)], detected using a stethoscope fitted with the same microphone, can be quantitatively characterized using systems analysis. The transfer functions of 40 normal workers (19 to 57 years old) were characterized, involving the analysis of 446 data points. The ECP waveform exhibits a pulsatile character with a slow respiratory component, which is superimposed on a biphasic recording that is synchronous with the cardiac cycle. The respiratory ECP waveform correlates with the instantaneous heart rate. The results also revealed that various fatigue-related risk factors may affect the mean magnitudes of the measured pressures and the delay transfer functions between CAP and ECP in the study population; these factors include systolic blood pressure, salivary amylase activity, age, sleep duration, postural changes, chronic fatigue, and pulse rate. PMID:23363133

Carotid baroreflex activation therapy produces a sustained fall in blood pressure in patients with resistant hypertension. Because the activation electrodes are implanted at the level of the carotid sinus, it is conceivable that the nearby located carotid body chemoreceptors are stimulated as well. Physiological stimulation of the carotid chemoreceptors not only stimulates respiration but also increases sympathetic activity, which may counteract the effects of baroreflex activation. The aim of this exploratory study is to investigate whether there is concomitant carotid chemoreflex activation during baroreflex activation therapy. Fifteen participants with the Rheos system were included in this single-center study. At arrival at the clinic, the device was switched off for 2 hours while patients were at rest. Subsequently, the device was switched on at 6 electric settings of high and low frequencies and amplitudes. Respiration and blood pressure measurements were performed during all device activation settings. Multilevel statistical models were adjusted for age, sex, body mass index, antihypertensive therapeutic index, sleep apnea, coronary artery disease, systolic blood pressure, and heart rate. There was no change in end-tidal carbon dioxide, partial pressure of carbon dioxide, breath duration, and breathing frequency during any of the electric settings with the device. Nevertheless, mean arterialpressure showed a highly significant decrease during electric activation (P<0.001). Carotid baroreflex activation therapy using the Rheos system did not stimulate respiration at several electric device activation energies, which suggests that there is no appreciable coactivation of carotid body chemoreceptors during device therapy. PMID:25941348

A 29-year-old Thai man presented with progressive dyspnea and evidence of pulmonary hypertension. Computed tomography was negative for pulmonary embolism. Cardiac catheterization confirmed the diagnosis of pulmonary arterial hypertension (mean pulmonary arterypressure 54?mm Hg, left ventricular end-diastolicpressure 4?mm Hg, and pulmonary vascular resistance 25 Wood units) without an intracardiac shunt. Two family members had been previously diagnosed with pulmonary hypertension. There was no evidence of left heart disease or respiratory disorders. Based on the definite diagnosis of pulmonary hypertension in 3 family members, heritable pulmonary arterial hypertension was confirmed. Genetic testing indicated no BMPR2 mutation. PMID:24948783

Absolute blood pressure (BP) values are not the only causes of adverse cardiovascular consequences. BP variability (BPV) has also been demonstrated to be a predictor of mortality for cardiovascular events; however, its determinants are still unknown. This study considers 426 subjects with ambulatory BP monitoring (ABPM) measuring 24-h, diurnal and nocturnal absolute BP values and their standard deviations of the mean, along with nocturnal fall, age, sex and current treatment. Patients were divided in two subgroups, controlled and uncontrolled BP, and BPV of patients with "true" and "false" resistant hypertension was also analyzed. Nocturnal and 24-h BPV were higher in the group with uncontrolled hypertension. Multiple regression analysis showed that absolute BP, age, nocturnal fall, but not sex predicted BPV. Patients with "true" resistant hypertension had greater BPV than "false" resistant hypertension patients. Absolute BP resulted as the main determinant of 24-h and nocturnal BPV but not daytime BPV. Also nocturnal BP fall and age resulted as predictors of BPV in treated and untreated patients. Patients with "true" resistant hypertension have a higher BPV, suggesting a higher sympathetic activation. Evidence is still limited regarding the importance of short-term BPV as a prognostic factor and assessment of BPV cannot yet represent a parameter for routine use in clinical practice. Future prospective trials are necessary to define which targets of BPV can be achieved with antihypertensive drugs and whether treatment-induced reduction in BPV is accompanied by a corresponding reduction in cardiovascular events. PMID:25555153

Transposition of great arteries is the consequence of abnormal aorticopulmonary septation. Animal embryonic data indicate that septation and elastogenesis are related events, but human and clinical data are not available. We tested the hypothesis that large artery elastic function was impaired in patients with transposition of great arteries. We studied 34 patients aged 9 to 19 years, 12+/-3 years after atrial switch operation; 14 patients aged 7 to 9 years, 8+/-1 years after arterial switch operation; and 108 healthy control subjects matched for age. Carotid arterydiastolic diameter and pulsatile distension were determined by echo wall-tracking; carotid blood pressure was measured by tonometry. Systolic pressure was higher and diastolicpressure was lower in patients than in controls. Patients with atrial and arterial switch repair were compared with their respective controls by 2-factor ANOVA. For patients with atrial switch repair versus control, stiffness index beta was 4.9+/-1.5 versus 3.1+/-1.0 (P<0.001); for patients witch arterial switch versus control, stiffness index beta was 3.8+/-1.1 versus 2.1+/-0.6 (P<0.001). Similar differences were observed for carotid compliance, distensibility, and incremental elastic modulus as well. The interaction term was not significant for any of the elastic variables, indicating that carotid stiffening was a characteristic of the condition and not the consequence of different hemodynamics. Carotid artery is markedly stiffer in patients, suggesting that impaired elastogenesis may constitute part of the congenital abnormality. Since carotid artery stiffness has been established as an independent cardiovascular risk factor, this condition may have consequences in the clinical management of these patients. PMID:16618837

In this paper we present an acquisition chain for the measurement of blood arterialpressure based on the oscillometric method. This method does not suffer from any limitation as the well-known auscultatory method and it is suited for wearable health monitoring systems. The device uses a pressure sensor whose signal is filtered, digitalized and analyzed by a microcontroller. Local analysis allows the evaluation of the systolic and diastolicpressure values which can be used ...

Backgrounds/Objectives : Noninvasive evaluation of elastic properties of vessel wall is hampered by the absence of methods to directly asse ss local elasticity. In order to invasively record the static pressure of carotid artery dur ing cardiac cycle in rabbit s and compare it with noninvasive technique, T–shaped tubes have been designed and constructed and calibrated. A noninvasive method to measure static pressure in arteries and finally estimate the elasticity of vessels is provided. Mat...

OBJECTIVE: Patients with cirrhosis have cardiovascular dysfunction and altered mechanical properties of large and small arteries. This study was undertaken in order to analyze the arterialpressure curve in relation to mean arterialpressure level, stroke volume, and severity of liver disease. MATERIALS AND METHODS: Forty-one patients with cirrhosis (Child-Turcotte classes A/B/C = 13/15/13) were studied during a hemodynamic investigation of portal hypertension. Fifteen patients without liver disease served as controls. We applied fast Fourier analysis to quantify the pressure components of the arterial curve, the harmonic Fourier coefficients (HFC). RESULTS: Mean arterialpressure was significantly reduced (91 vs. 98 mmHg, p < 0.001) and stroke volume was significantly increased (94 vs. 78 ml, p < 0.001) in patients with cirrhosis versus controls. The HFC were significantly lower in patients with cirrhosis than in controls (-15 to -24%, p < 0.002), except for the fourth HFC, which was significantly increased (+28%, p < 0.02). In contrast to controls, which showed a highly significant effect of the level of arterialpressure on their HFC (p < 0.001), patients with cirrhosis did not show pressure or stroke volume dependence on their HFC, indicating an overall compliant and slow reflective arterial vascular bed. The initial rise in pulse pressure (dP/dt) was inversely related to the Child-Turcotte score (p < 0.05), and the HFC were borderline significantly related to this score (p = 0.07). CONCLUSIONS: The arterial pulsation in cirrhosis is qualitatively changed with reduced pulse reflections, which may protect against manifest cardiac failure in patients with advanced cirrhosis.

Arterial hypertension is the most important risk factor for coronary artery disease (CAD). There is a high coincidence of both diseases, whereby both impair coronary microcirculatory function synergistically, which can be measured functionally by decreased coronary flow reserve. This dysfunction leads to permanent damage to the left ventricular myocardium. Lifestyle changes play a central role in the primary and secondary prevention of CAD. Additionally, there are well-established options for antihypertensive drug therapy, which should be combined with aspirin and statins. Pharmacological treatment should follow distinctive blood pressure goals in relation to the severity of CAD. Particular attention is paid in this context to the relation between diastolic blood pressure values and cardiovascular endpoints, which displays a j-shaped curve with the lowest risk at levels between 70 and 90 mmHg. PMID:22430321

Pathophysiology of heart failure has been considered to be a damaged state of systolic function of the heart followed by a state of low cardiac output that is, systolic heart failure. Even if systolic function is preserved, left ventricular filling in diastole can be impeded and resulted in elevation of filling pressure and symptoms of heart failure. This kind of heart failure is called diastolic heart failure. Nowadays, diastolic heart failure is referred to as heart failure with preserved e...

Usefulness of diastolic dysfunction after adenosine stress for detecting coronary stenosis has not been defined. The diagnostic accuracy of a combination of myocardial perfusion and diastolic function, as defined by prolongation of time to peak-filling rate (TTPF)/R-R and myocardial perfusion alone for the detection of coronary restenosis, was evaluated. We used rest 201Tl/ adenosine stress 99mTc-tetrofosmin myocardial perfusion single-photon emission computed tomography (SPECT) in 70 patients. Patients were divided into the following 4 groups: 20 patients with normal SPECT without stent (Control group), 20 patients showing normal SPECT without coronary restenosis (Group 1), 16 patients showing significant coronary restenosis and myocardial ischemia (Group 2a) and 14 patients showing significant coronary restenosis without myocardial ischemia (Group 2b). The TTPF, which was calculated by quantitative gated SPECT (QGS)/R-R, was not different between after stress and at rest in Control group (0.18±0.02 vs 0.19±0.04, P=NS). The TTPF/R-R after stress was significantly lower than that at rest in Group 1 (0.17±0.02 vs 0.18±0.03, P<0.05), but TTPF/R-R after stress was significantly higher than that at rest in Groups 2a and 2b (0.22±0.03 vs 0.16±0.03, P<0.001 in Group 2a and 0.19±0.02 vs 0.16±0.02, P<0.001 in Group 2b, respectively). Diagnostic accuracy improved from 72% to 92% when prolongation of TTPF/R-R was taken into account (P<0.001). Diastaken into account (P<0.001). Diastolic dysfunction after stress was an accurate marker for detecting significant restenosis following stent implantation. (author)

Full Text Available Athletes are susceptible to a wide variety of traumatic and non-traumatic vascular injuries to the lower limb. This paper aims to predict the three-dimensional flow pattern of blood through an S-shaped geometrical artery model. This model has created by using Fluid Structure Interaction (FSI software. The modeling of the geometrical S-shaped artery is suitable for understanding the pattern of blood flow under constant normal blood pressure. In this study, a numerical method is used that works on the assumption that the blood is incompressible and Newtonian; thus, a laminar type of flow can be considered. The authors have compared the results with a previous study with FSI validation simulation. The validation and verification of the simulation studies is performed by comparing the maximum velocity at t = 0.4 s, because at this time, the blood accelerates rapidly. In addition, the resulting blood flow at various times, under the same boundary conditions in the S-shaped geometrical artery model, is presented. The graph shows that velocity increases linearly with time. Thus, it can be concluded that the flow of blood increases with respect to the pressure inside the body.

Full Text Available Introduction: Hypertrophied tonsils and adenoids may cause upper airway obstruction and cardio-pulmonary complications due to pulmonary arterial hypertension. The aim of this study was to determine the correlation between mean pulmonary arterialpressure (mPAP and selected adenotonsilar hypertrophy indexes. Materials and Methods: Thirty two patients with upper-airway obstruction resulting from hypertrophied tonsils and adenoids were included in our study. Mean pulmonary arterialpressure was measured by a non-invasive method using color doppler echocardiography. Upper airway obstruction was evaluated by clinical OSA (obstructive sleep apnea scoring and also adenoidal-nasopharyngeal (A/N ratio in the lateral neck radiography. Results: Fifty percent of the patients with a normal OSA score, 20% of those with a suspected OSA score and also 50% of cases with OSA had pulmonary hypertension (mPAP>20mmHg which was not statistically significant (P=0.198. Mean Adenoidal-nasopharyngeal ratio in patients with a normal mPAP (mPAP?20mmHg was 0.61±0.048 and it was 0.75±0.09 in those with pulmonary hypertension; the difference was statistically significant (P=0.016. Conclusion: It seems that A/N ratio could be used as a predicting factor for increased mPAP in children with upper airway obstruction and a pediatric cardiologist consultation may be necessary before some surgical interventions.

Full Text Available Abstract Introduction We describe a case of early and persistent reverse end-diastolic flow in the middle cerebral artery in a fetus with severe ascites. These features are associated with a rare liver malformation known as ductal plate malformation. Case presentation A 28-year-old Caucasian woman was referred to our high-risk obstetric unit at 24 weeks' gestation for fetal ascites detected during a routine ultrasound examination. During her hospitalization we performed medical investigations, including a fetal paracentesis, to detect the etiology of fetal ascites. The cause of fetal ascites (then considered non-immune or idiopathic was not evident, but a subsequent ultrasound examination at 27 weeks' gestation showed a reverse end-diastolic flow in the middle cerebral artery without any other Doppler abnormalities. A cesarean section was performed at 28 weeks' gestation because of the compromised fetal condition. An autopsy revealed a rare malformation of intrahepatic bile ducts known as ductal plate malformation. Conclusion Persistent reverse flow in the middle cerebral artery should be considered a marker of adverse pregnancy outcome. We recommend careful ultrasound monitoring in the presence of this ultrasonographic sign to exclude any other cause of increased intracranial pressure. To better understand the nature of these ultrasonographic signs, additional reports are deemed necessary. In fact in our case, as confirmed by histopathological examination, the fetal condition was extremely compromised due to failure of the fetal liver. Ductal plate malformation altered the liver structures causing hypoproteinemia and probably portal hypertension. These two conditions therefore explain the severe hydrops that compromised the fetal situation.

Altered frequency of slow (0.04-0.15Hz) arterialpressure and R-R interval oscillations has been observed in various diseases but the mechanisms for this frequency shift are unclear. The median (Med) frequencies of slow R-R interval and blood pressure (BP) oscillations were recorded in 11 healthy subjects with paced breathing (0.25Hz) during muscle metaboreflex and baroreflex mediated sympathetic stimuli: 1) handgrip exercise (HG) followed by post-exercise circulatory occlusion (PECO), 2) handgrip exercise during ischemia by circulatory occlusion (IHG) and 3) passive head-up tilt (TILT). Med(BP) shifted to the higher frequency during HG, PECO and IHG (from 0.070+/-0.009Hz to 0.088+/-0.013, 0.085+/-0.015 and 0.099+/-0.013Hz, respectively, p<0.01 for all) but not during TILT (0.078+/-0.012Hz). Similarly, Med(R-R) shifted to the higher frequency during HG, PECO and IHG (from 0.072+/-0.009Hz to 0.085+/-0.014, 0.085+/-0.016 and 0.095+/-0.015Hz, respectively, p<0.01 for all) but not during TILT (0.075+/-0.012Hz). Med(BP) and Med(R-R) were higher during IHG compared to HG and lower during TILT compared to both HG and IHG (p<0.01 for all). We conclude that the sympathetic stimulus induced by muscle metaboreflex is an important mechanism increasing the frequency of slow oscillations in arterialpressure and R-R intervals. The present results give new insight to understand the physiology underlying the frequency of slow arterialpressure and R-R interval oscillations. PMID:19767247

Mean arterialpressure (MAP) is a critical hemodynamic factor. The absence of proper regulation of MAP can have important pathophysiological consequences. Low MAP can cause inadequate blood flow to organs, syncope, and shock. On the other hand, elevated MAP contributes to increased oxygen demand by the heart, ventricular remodeling, vascular injury, end organ damage, and stroke. The arterial baroreflex system is a key controller of MAP and is a complex system. It can be considered in its entirety as an integrative physiological system or in terms of its regulated component parts. Those component parts include MAP, mechanosensory transduction, afferent pathways, central neural circuits, efferent pathways, receptor pharmacology, integration with other key homeostatic inputs, molecular biology, and/or other elements. This chapter provides an overview of each of these individual components but stresses the importance of the integrative nature of this reflex. In addition, this chapter explores common measurement techniques for the baroreflex and explores the baroreflex in diseases. PMID:24095118

The pulmonary arterioles react to hypoxia by contraction and to increased pressure and volume by hypertrophy of the muscular wall, referred to as pulmonary vascular remodeling, both of which increase vascular resistance and result in increased pulmonary arterialpressure. Heart muscle reacts to increased pressure by hypertrophy of cardiac myocytes and thickening of the muscular wall. The heart responds to increased volume by dilation of the chamber that may result in physiologic or pathologic hypertrophy of the muscle wall. Heart muscle cells are very sensitive to hypoxia or other insults, and this may result in death of individual cardiac myocytes with lengthening and thinning of the remaining heart muscle cells and dilation of the chamber in a process called dilated cardiomyopathy. PMID:17435039

Full Text Available Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC measurement by the pulmonary artery catheter (PAC. However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterialpressure-based cardiac output (COAP device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU using COPAC as the method of reference. Methods We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 ± 18.8 years, who required both arterial and pulmonary arterypressure monitoring. COPAC measurements were performed at least every 4 hours and calculated as the average of 3 measurements, while COAP values were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman. Results A total of 164 coupled measurements were obtained. Absolute values of COPAC ranged from 2.80 to 10.80 l/min (mean 5.93 ± 1.55 l/min. The bias and limits of agreement between COPAC and COAP for unequal numbers of replicates was 0.02 ± 2.92 l/min. The percentage error between COPAC and COAP was 49.3%. The bias between percentage changes in COPAC (?COPAC and percentage changes in COAP (?COAP for consecutive measurements was -0.70% ± 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p PAC and ?COAP was 0.46 (p Conclusion Although the COAP algorithm shows a minimal bias with COPAC over a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore, the used algorithm (V 1.03 failed to demonstrate an acceptable accuracy in comparison to the clinical standard of cardiac output determination.

Full Text Available Abstract Background Diabetes is a global epidemic. Cardiovascular disease (CVD is one of the most prevalent consequences of diabetes. Nutrition is considered a modifiable risk factor for CVD, particularly for individuals with diabetes; albeit, there is little consensus on the role of carbohydrates, proteins and fats for arterial health for persons with or without diabetes. In this study, we examined the association of macronutrients with arterial pulse pressure (APP, a surrogate measure of arterial health by diabetes status and race. Methods Participants were 892 Mexican Americans (MA, 1059 Black, non-Hispanics (BNH and 2473 White, non-Hispanics (WNH with and without diabetes of a weighted sample from the National Nutrition and Health Examination Survey (NHANES 2007-2008. The cross-sectional analysis was performed with IBM-SPSS version 18 with the complex sample analysis module. The two-year sample weight for the sub-sample with laboratory values was applied to reduce bias and approximate a nationally, representative sample. Arterial stiffness was assessed by arterial pulse pressure (APP. Results APP was higher for MA [B = 0.063 (95% CI 0.015 to 0.111, p = 0.013] and BNH [B = 0.044 (95% CI 0.006 to 0.082, p = 0.018] than WNH, controlling for diabetes, age, gender, body mass index (BMI, fiber intake, energy intake (Kcal and smoking. A two-way interaction of diabetes by carbohydrate intake (grams was inversely associated with APP [B = -1.18 (95% CI -0.178 to -0.058, p = 0.001], controlling for race, age, gender, BMI, Kcal and smoking. BNH with diabetes who consumed more mono-unsaturated fatty acids (MUFA than WNH with diabetes had lower APP [B = -0.112 (95%CI-0.179 to -0.045, p = 0.003] adjusting for saturated fatty acids, Kcal, age, gender, BMI and smoking. Conclusion Higher MUFA and carbohydrate intake for persons with diabetes reflecting lower APP may be due to replacement of saturated fats with CHO and MUFA. The associations of APP with diabetes, race and dietary intake need to be confirmed with intervention and prospective studies. Confirmation of these results would suggest that dietary interventions for minorities with diabetes may improve arterial health.

Full Text Available Objective: Chronic obstructive lung disease (COPD is a systemic disease characterised by airflow limitation that is not fully reversible. Right ventricular diastolic function (rvdf was investigated in COPD.Material and Methods: Study groups consisted of 40 patients with COPD and 24 healthy controls. All subjects performed respiratory function test and doppler echocardiography. Results: There was no statistical difference between patient and control groups with respect to tricuspid annular systolic velocity (S, tricuspid annulus early diastolic filling velocity (E and tricuspid annulus late diastolic velocity (A (p>0.05. For E/A ratio and ?VRT, there was a statistical difference between groups (p=0.05, p=0.0001. There was a positive correlation between FEV1 and E/A ratio (r=0.409, p=0.009. There was no statistically significant correlation between other parameters of Echocardiography (Echo, RFT and arterial blood gas (ABG analysis comparisons. Decrease in E and E/A ratio in COPD whose SatO2?%90 was statistically significant compared to patients with SatO2>%90 (p=0.002. Decreases in E and E/A rates were significant between COPD cases with PH (pulmonary arterypressure PABsis>30 mmHg, and those without PH (p=0.016, p=0.01. There was no statistically significant correlation between PABsis and FEV1 and FEV1/FVC. There was a negative correlation between PABsis and pO2, and positive correlation between PABsis and pCO2 (p=0.006, p=0.029. There was a positive correlation between FEV1, pO2 and satO2 (p=0.018, p=0.001. Conclusion: As a result, we concluded that, in order to evulate right ventricular functions in COPD cases, we must not only consider systolic functions but also examining the diastolic functions is important. Doppler-Echo proved to be favorable in evaluating rvdf in all COPD patients.

Arterial walls are a multilayer structures with nonlinear material characteristics. Furthermore, residual stresses exist in unloaded state (zero-pressure condition) and they affect arterial behavior. To investigate these phenomena a number of theoretical and numerical studies were performed, however no experimental validation was proposed and realized yet. We cannot get rid of residual stresses without damaging the arterial segment. In this paper we propose a novel experiment to validate a numerical model of artery with residual stresses. The inspiration for our study originates from experiments made by Dobrin on dogs' arteries (1999). We applied the idea of turning the artery inside out. After such an operation the sequence of layer is reversed and the residual stresses are re-ordered. We performed several pressure-inflation tests on human Common Carotid Arteries (CCA) in normal and inverted configurations. The nonlinear responses of arterial behavior were obtained and compared to the numerical model. Computer simulations were carried out using the commercial software which applied the finite element method (FEM). Then, these results were discussed.

Indirectly measured blood pressure at the wrist or upper arm was compared with directly measured values in the aortic arch during routinely performed diagnostic cardiac catheterization in 100 patients (31-80 years, mean 59.3 years, 60% males). The noninvasive measurements were carried out by oscillometric devices, NAiS Blood Pressure Watch for measurements at the wrist, and Hestia OZ80 at the upper arm. Systolic blood pressure measured at the wrist was 4.3 +/- 14.1 mm Hg, and the diastolic value 6.0 +/- 8.9 mm Hg higher than when measured at the aortic arch; the difference was significant in both cases. Correlation coefficients were 0.85 for systolic and 0.71 for diastolic blood pressure. In 16% of the patients the systolic blood pressure at the wrist differed more than +/- 20 mm Hg. The diastolic blood pressure at the wrist measured more than +/- 20 mm Hg higher than in the aorta in 5% of the patients. At the upper arm mean systolic values were not different to the aorta. The diastolicpressure was 9.3 +/- 9.8 mm Hg higher in the aorta than at the upper arm. To verify the accuracy of values measured with the NAiS Blood Pressure Watch compared with the standard technique at the upper arm, sequential measurements were made at wrist and ipsilateral upper arm in the same group of 100 patients. The systolic blood pressure at the left wrist was 3.4 +/- 13.3 mm Hg higher and the diastolicpressure 3.8 +/- 9.5 mm Hg lower than at the upper arm. Only 53% of systolic values lay within a range of +/- 10 mm Hg. The correspondence between wrist and upper arm values was better for diastolic blood pressure, the values differing by less than +/- 10 mm Hg in two-thirds of patients. Self-measurement of arterial blood pressure with an oscillometric device at the wrist can be recommended only in individual cases with a difference of simultaneously measured values at the upper arm of less than +/- 10 mm Hg for systolic and diastolic blood pressures. The standard method for indirectly measuring arterial blood pressure remains the measurement at the upper arm site, which nevertheless showed a systolic pseudohypertension (deviation of more than 10 mm Hg) in comparison to the invasively measured values in 15% of our selected patients and a diastolic pseudohypertension (deviation of more than 15 mm Hg) in 23% of the patients. PMID:8525669

Background/Aims The aim of this study was to evaluate whether supplementation of high doses of cholecalciferol for two months in normotensive rats results in increased systolic arterialpressure and which are the mechanisms involved. Specifically, this study assesses the potential effect on cardiac output as well as the changes in aortic structure and functional properties. Methods Male Wistar rats were divided into three groups: 1) Control group (C, n?=?20), with no supplementation of vitamin D, 2) VD3 (n?=?19), supplemented with 3,000 IU vitamin D/kg of chow; 3) VD10 (n?=?21), supplemented with 10,000 IU vitamin D/kg of chow. After two months, echocardiographic analyses, measurements of systolic arterialpressure (SAP), vascular reactivity, reactive oxygen species (ROS) generation, mechanical properties, histological analysis and metalloproteinase-2 and -9 activity were performed. Results SAP was higher in VD3 and VD10 than in C rats (p?=?0.001). Echocardiographic variables were not different among groups. Responses to phenylephrine in endothelium-denuded aortas was higher in VD3 compared to the C group (p?=?0.041). Vascular relaxation induced by acetylcholine (p?=?0.023) and sodium nitroprusside (p?=?0.005) was impaired in both supplemented groups compared to the C group and apocynin treatment reversed impaired vasodilation. Collagen volume fraction (<0.001) and MMP-2 activity (p?=?0.025) was higher in VD10 group compared to the VD3 group. Elastin volume fraction was lower in VD10 than in C and yield point was lower in VD3 than in C. Conclusion Our findings support the view that vitamin D supplementation increases arterialpressure in normotensive rats and this is associated with structural and functional vascular changes, modulated by NADPH oxidase, nitric oxide, and extracellular matrix components. PMID:24921930

We conducted a genome-wide association study meta-analysis of mean arterialpressure and pulse pressure among 26,600 East Asian participants (stage-1) followed by replication study of up to 28,783 participants (stage-2). For novel loci, statistical significance was determined by a P

It is known that a large proportion of patients with arterial hypertension are undertreated. This may result in an increase of the incidence of cardiovascular events. On the other hand, aggressive reduction of blood pressure may increase cardiovascular events (J-curve phenomenon) in certain populations. This phenomenon may be seen in patients with coronary artery disease and left ventricular hypertrophy when the diastolic blood pressure decreases below 70-80 mm Hg, and the systolic blood pressure decreases below 130 mm Hg. This phenomenon is not seen in patients with stroke or renal disease. Thus, a safer and more conservative strategy should be applied in patients with coronary artery disease, left ventricular hypertrophy, elderly, and in patients with isolated systolic hypertension. This is depicted in the recently published European Society of Hypertension/European Society of Cardiology guidelines in which higher targets of blood pressure are suggested in certain cardiovascular diseases and in the elderly. PMID:25227573

To analyze the early and late left ventricular diastolic function in coronary artery disease (CAD), technetium-99m gated equilibrium radionuclide ventriculography was performed in 27 patients with CAD, including 8 old myocardial infarction (group GM), 19 non-myocardial infarction (group GN), and 12 control subjects (group G1). Parameters of diastolic function was obtained from second derivative analysis of time-activity curve. In GM group, indexes of systolic and diastolic function was significantly depressed than those of GN and G1 group (P<0.0001)

Early peak diastolic filling rate (PFR) of the left ventricle (LV) is said to be a sensitive index of LV dysfunction in patients with coronary disease, hypertension and hypertrophic cardiomyopathy. Radionuclide (RN0 multigated PFR was measured in 20 normal volunteers (13 males, 7 females, mean age 31 yrs., range 20-43) at rest and during supine bicycle exercise conducted to a symptomatic end-point. At rest, RN PFR was 3.4 +- SD 0.4 end-diastolic vols./sec (range 3.1 - 3.6). During exercise all normal volunteers had a progressive and numerically and statistically significant increase in PFR. Stepwise multiple linear regression (BMPD2R) was applied to the rest and exercise PFR data to develop a linear model describing the main determinants of the RN PFR. The potential independent variables which were included in the model were heart rate (HR), ejection fraction (EF), systolic arterialpressure, systolic ejection rate and exercise stage. Ranking of variables for prediction of RN PFR, and exclusion of less important variables, was done by F value criteria. The final multivariate equation was: LVPFR = -3.84437 + 0.03834 HR + 0.07537 LVEF. The model fit was highly significant (p<0.001), and accounted for 89 per cent of variability in the PFR. The authors conclude that the left ventricular peak filling rate is critically determined by heart rate and by ejection fraction at rest and during exercise

Full Text Available INTRODUÇÃO: O grupo das doenças cardiovasculares tem sido apontado como a principal causa de óbito no Brasil desde os anos 70, sendo a hipertensão arterial sistêmica (HAS o fator de risco mais importante para esse grupo. Entre os trabalhadores observa-se correlação negativa entre o status ocupacional e a pressão arterial. Tais fatos ressaltam a importância do conhecimento da distribuição da pressão arterial sistêmica entre os distintos grupos profissionais. Assim, foi realizado estudo para descrever o status pressórico de uma população homogênea e estável de trabalhadores do setor secundário da economia, pouco especializados e que ganham baixos salários, estabelecendo a prevalência da HAS nesse grupo específico, relacionando-a com algumas covariáveis biológicas e socioeconômicas, e comparando-a com a prevalência de HAS em outros grupos profissionais no Brasil. MÉTODO: Foram estudados 73 trabalhadores regularmente empregados em julho de 1993 em um curtume situado no Município de Botucatu, cidade de médio porte da região Centro-Oeste do Estado de São Paulo, os quais foram submetidos a exame antropométrico, aferição de pressão arterial, anamnese e exame clínico. Os resultados foram comparados com os obtidos em estudos semelhantes, controlando-se o confundimento da idade por intermédio de diferentes técnicas. RESULTADOS: A prevalência bruta da HAS encontrada foi de 56,1%, sendo 15,8% a prevalência de hipertensão sistólica isolada. Ambas se associaram ao etilismo e ao tabagismo na população estudada. DISCUSSÃO: A prevalência da hipertensão foi consideravelmente alta e significativamente maior do que a encontrada em outros grupos de trabalhadores estudados no Brasil. Tal achado ressalta a necessidade da continuidade da investigação, objetivando o isolamento dos fatores implicados na elevação pressórica do grupo estudado.INTRODUCTION: Cardiovascular diseases have been shown to be the leading cause of death in Brazil since the 1970s. High blood pressure has been the major risk factor among the above mentioned diseases. A negative correlation between occupational qualification and blood pressure has been observed among workers. The above mentioned facts bring out the importance of the knowledge of high blood pressure distribution among the different occupational groups. The aim of the present study was to describe the distribution of blood pressure in stable and homogeneous population of unskilled, low wage larning industrial workers. The Prevalence of high blood pressure was established for this specific group. This prevalence was also related to some biological and socio-economical covariates as compared with that among other occupational groups in Brazil. METHOD: The subjects were 73 active employees at a tannery in Botucatu, state of S.Paulo, Brazil, in July 1993. These subjects underwent blood pressure measurements, anamnesis and clinical examination. The results were compared with those of similar studies carried out in elsewhere Brazil. Age confounding was controlled by different techniques. RESULT: The crude prevalence of high blood pressure detected in this group of workers was of 56.1%, with 15.8% of isolated systolic hypertension. Alcohol abuse and smoking were associated with high blood pressure and isolated systolic hypertension in the population studied. DISCUSSION: Prevalence of hypertension in the group studied is significantly higher than that observed in other groups of workers studied in Brazil. Such a finding points to the need for further investigation so as to isolate those factors involved in the increased blood pressure found in this group.

Full Text Available Backgrounds/Objectives : Noninvasive evaluation of elastic properties of vessel wall is hampered by the absence of methods to directly asse ss local elasticity. In order to invasively record the static pressure of carotid artery dur ing cardiac cycle in rabbit s and compare it with noninvasive technique, T–shaped tubes have been designed and constructed and calibrated. A noninvasive method to measure static pressure in arteries and finally estimate the elasticity of vessels is provided. Materials and Methods: In male white rabbits, we estimated the static pressure changes in carotid artery noninvasively by measuring blood flow velocities throughout cardiac cycle using Color Doppler Ultrasound. The blood flow ve locities were converted to static pressure changes by using energy conservation low. The st atic pressure changes of arterial wall were estimated. These parameters were compared wi th measured actual static pressure changes using a T-shaped tube, that was inserted into the carotid artery and the static pressure change was measured in the side br anch of the tube. The elastic parameters in both methods were calculated and compared by pa ired t-test statistical analysis. Results: Statistical analysis of static pressure c hanges and elastic parameters in both methods showed that there was no significant difference between the two methods. Conclusion: By applying this noninvasive approach, we can estimate elastic parameters in arteries of normal people and patients with, or at risk of developing atherosclerosis for determination of disease extent. We propose this noninvasive method as an accurate and safe way suitable for screening of large popula tions of young and symptom-free individuals.

Full Text Available Arterial hypertension begins in childhood and may continue, without intervention, throughout adulthood with severe health sequelae.The base of timely diagnosis is the systematic blood pressure (BP measurement. Background: The study aims at revealing the level of parental and community awareness and testing the value of a simple measurement in uncovering children who need further assessment when performing an in-hospital BP screening. Methods: BP was measured in 600 children (0 - 17 yr, mean age 5.1 ± 4.3 yr at a Children’s hospital. Parents were asked to fill in a specially structured questionnaire. Results: In 47.2% of the subjects (40.1% of them were Greeks and 60.6% foreigners, BP had never been checked before (p arterial BP had never been checked before. Surprisingly, a health certificate was issued for school purposes for 81.2% of the schoolchildren of this study, and 75.3% of the enrolled children were allowed to participate in sports clubs without first checking BP. Moreover, parents demonstrated a low level of alertness with respect to paediatric hypertension. Conclusions: Simple arterial BP measurements can ensure early detection and thus early referral to specialists.

During an antiorthostatic posture change, left atrial (LA) diameter and arterial pulse pressure (PP) increase, and plasma arginine vasopressin (AVP) is suppressed. By comparing the effects of a 15-min posture change from seated to supine with those of 15-min seated negative pressure breathing in eight healthy males, we tested the hypothesis that with similar increases in LA diameter, suppression of AVP release is dependent on the degree of increase in PP. LA diameter increased similarly during the posture change and negative pressure breathing (-9 to -24 mmHg) from between 30 and 31 +/- 1 to 34 +/- 1 mm (P <0.05). The increase in PP from 38 +/- 2 to 44 +/- 2 mmHg (P <0.05) was sustained during the posture change but only increased during the initial 5 min of negative pressure breathing from 36 +/- 3 to 42 +/- 3 mmHg (P <0.05). Aortic transmural pressure decreased during the posture change and increased during negative pressure breathing. Plasma AVP was suppressed to a lower value during the posture change (from 1.5 +/- 0.3 to 1.2 +/- 0.2 pg/ml, P <0.05) than during negative pressure breathing (from 1.5 +/- 0.3 to 1.4 +/- 0.3 pg/ml). Plasma norepinephrine was decreased similarly during the posture change and negative pressure breathing compared with seated control. In conclusion, the results are in compliance with the hypothesis that during maneuvers with similar cardiac distension, suppression of AVP release is dependent on the increase in PP and, furthermore, probably unaffected by static aortic baroreceptor stimulation.

The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel (SPPH) as measured with a photocell. Thirty-two patients (35 feet with ulcerations) had diabetes mellitus. The treatment was conservative. In 42 feet the ulcers healed after an average period of 5.8 months; in 24 feet major amputation became necessary after an average of 4.3 months. The frequency of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two cases (9%) healed. Of the 11 cases with SDBP of 20 to 29 mmHg seven cases (64%) healed and of the 33 cases with SDBP of30 mmHg or above all cases (100%) healed. There was no significant difference between the 35 diabetic feet and the 31 non-diabetic feet as regards the healing rates, although infection and peripheral neuropathy were frequent in the diabetic group. The data show that the systolic digital blood pressure is a particularly valuable prognostic parameter.

The aim of our study was to examine whether there is an association between blood pressure reactivity to the cold pressor test in African Americans who engaged in different levels of physical activity. We examined the systolic pressure, diastolicpressure, mean arterial blood pressure, heart rate, cardiac index, total peripheral resistance, and forearm blood flow during a two-minute cold pressor test in 15 aerobic, physically active and 15 physically inactive, normotensive young adult African...

Nighttime blood pressure (BP) dipping can be quantified as the ratio of mean nighttime (sleep) BP to mean daytime (awake) BP. People whose dipping ratio is 0.90 have been referred to as nondippers, and nondipping is associated with cardiovascular disease events. We examined the relationship between systolic nighttime BP dipping in young adults and presence of coronary artery calcium (CAC) 10-15 years later using data from the ambulatory BP monitoring substudy of the Coronary Artery Risk Devel...

AIM: To find out the correlation between clinical grade of hepaticencephalopathy and different serum ammonia levels, namely,serum arterial ammonia, serum venous ammonia, partial pressureof ammonia in arterial plasma and partial pressure of ammonia invenous plasma.METHODS: After informed consent from patients or their relatives,100 patients in hepatic encephalopathy due to advanced liver disease,were examined for their clinical grade of hepatic encephalopathywithin 24 hours of admission. Fasti...

In this investigation, we assessed the effects of physical training on exercise-induced systemic and pulmonary hemodynamic changes under hypobaric hypoxia in catheter-implanted rats. We made continuous measurements of pulmonary and systemic arterialpressures during progressive treadmill exercises under hypobaric hypoxia (equivalent to altitudes of 2500 and 5500 m) in 46 control and 41 trained rats. Trained rats were exercised on two running schedules: 4 weeks (4-trained) and 6 weeks (6-trained). Both these groups of trained rats were exercised for the same length of running time each day. The increase in resting mean pulmonary arterialpressure(overline {P_{pa} } ) with increasing equivalent altitude was lower in the two trained groups than in the control group. The increase in(overline {P_{pa} } ) with progressive intensity of exercise was lower in the 6-trained than in the 4-trained and control groups at 610 and 2500 m. The 6-trained rats showed higher pH, P a CO 2 and O2 saturation in their blood than did the control group, whereas the P a O 2 was less. Lung tissue cyclic AMP concentration at rest was higher in the 6-trained than in the control group. Finally, it may be noted that exercise-induced lung tissue vasodilator responses seem to be enhanced in well-trained rats under both normobaric normoxia and hypobaric hypoxia. This study indicates that exercise training may be useful in preventing pulmonary hypertension resulting from both hypoxia and exercise.

Full Text Available This work describes the biophysical basis of blood vessels' wall dynamics and reports a methodology developed in our laboratory to characterize mechanical vessels' wall properties and those of vascular prostheses. Our study includes in vitro measurements of arteries, veins and ePTFE conduits placed [...] in a circulating loop. Segments are allowed to equilibrate for a period of 15 minutes under a steady state of flow (150 ml/min) and a mean pressure of 93 mmHg, at a stretching rate of 110 beats/min. Data analysis consisted in obtaining pressure-diameter loop in order to calculate: Incremental elastic modulus, wall viscosity, Peterson modulus, pulse wave velocity, characteristic impedance, stiffness index, cross sectional compliance and distensibility. Incremental elastic modulus of ePTFE (48.56±0.82 10(7)dyn/cm²) was significantly higher than that of the veins (26.19±19.90 10(7)dyn/cm²) and that of the arteries (4.06±2.55 10(7)dyn/cm²). This is an important approach, since mechanical wall dynamics plays a major role in vascular disease.

Full Text Available The maintenance of arterialpressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-mo [...] ment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterialpressure (baroreflex), blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes), and changes in blood-gas composition (chemoreceptor reflex). The importance of the integration of these cardiovascular reflexes is well understood and it is clear that processing mainly occurs in the nucleus tractus solitarii, although the mechanism is poorly understood. There are several indications that the interactions of baroreflex, chemoreflex and Bezold-Jarisch reflex inputs, and the central nervous system control the activity of autonomic preganglionic neurons through parallel afferent and efferent pathways to achieve cardiovascular homeostasis. It is surprising that so little appears in the literature about the integration of these neural reflexes in cardiovascular function. Thus, our purpose was to review the interplay between peripheral neural reflex mechanisms of arterial blood pressure and blood volume regulation in physiological and pathophysiological states. Special emphasis is placed on the experimental model of arterial hypertension induced by N-nitro-L-arginine methyl ester (L-NAME) in which the interplay of these three reflexes is demonstrable

Full Text Available The maintenance of arterialpressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterialpressure (baroreflex, blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes, and changes in blood-gas composition (chemoreceptor reflex. The importance of the integration of these cardiovascular reflexes is well understood and it is clear that processing mainly occurs in the nucleus tractus solitarii, although the mechanism is poorly understood. There are several indications that the interactions of baroreflex, chemoreflex and Bezold-Jarisch reflex inputs, and the central nervous system control the activity of autonomic preganglionic neurons through parallel afferent and efferent pathways to achieve cardiovascular homeostasis. It is surprising that so little appears in the literature about the integration of these neural reflexes in cardiovascular function. Thus, our purpose was to review the interplay between peripheral neural reflex mechanisms of arterial blood pressure and blood volume regulation in physiological and pathophysiological states. Special emphasis is placed on the experimental model of arterial hypertension induced by N-nitro-L-arginine methyl ester (L-NAME in which the interplay of these three reflexes is demonstrable

The blood pressure J-curve discussion has been ongoing for more than 30 years, yet there are still questions in need of definitive answers. On one hand, existing antihypertensive therapy studies provide strong evidence for J-curve-shaped relationships between both diastolic and systolic blood pressure and primary outcomes in the general hypertensive patient population, as well as in high-risk populations, including subjects with coronary artery disease, diabetes mellitus, left ventricular hy...

Abstract It is generally assumed that one reason why white matter injury is common in preterm infants is the relatively poor vascular supply. Aim: To examine whether blood flow to the white matter is relatively more reduced at low blood pressure than is blood flow to the brain as a whole. Methods: Thirteen normoxic preterm infants had blood flow imaging on 16 occasions with single-photon emission computed tomography (SPECT) using 99Tc labelled hexa-methylpropylenamide oxime (HMPAO) as the tracer. Gestational age was 26-32 weeks. Transcutaneous carbon dioxide was between 4.7 and 8.5 kPa and mean arterial blood pressure between 22 and 55 mmHg. Results: There was no statistically significant direct relation between white matter blood flow percentage and any of the variables. Using non-linear regression, however, assuming a plateau over a certain blood pressure threshold and a positive slope below this threshold, the relation to white matter flow percentage was statistically significant (p = 0.02). The threshold was 29 mmHg (95% confidence limits 26-33). Conclusion: Our analysis supports the concept of periventricular white matter as selectively vulnerable to ischaemia during episodes of low blood pressure.

The mechanisms by which heat stress impairs the control of blood pressure leading to compromised orthostatic tolerance are not thoroughly understood. A possible mechanism may be an attenuated blood pressure response to a given increase in sympathetic activity. This study tested the hypothesis that whole body heating attenuates the blood pressure response to a non-baroreflex-mediated sympathoexcitatory stimulus. Ten healthy subjects were instrumented for the measurement of integrated muscle sympathetic nerve activity (MSNA), mean arterial blood pressure (MAP), heart rate, sweat rate, and forearm skin blood flow. Subjects were exposed to a cold pressor test (CPT) by immersing a hand in an ice water slurry for 3 min while otherwise normothermic and while heat stressed (i.e., increase core temperature ~0.7°C via water-perfused suit). Mean responses from the final minute of the CPT were evaluated. In both thermal conditions CPT induced significant increases in MSNA and MAP without altering heart rate. Although the increase in MSNA to the CPT was similar between thermal conditions (normothermia: ?14.0 ± 2.6; heat stress: ?19.1 ± 2.6 bursts/min; P = 0.09), the accompanying increase in MAP was attenuated when subjects were heat stressed (normothermia: ?25.6 ± 2.3, heat stress: ?13.4 ± 3.0 mmHg; P < 0.001). The results demonstrate that heat stress can attenuate the pressor response to a sympathoexcitatory stimulus. PMID:20798269

Full Text Available [...] Abstract in english Background: Hypertension is the main independent cardiovascular risk factor. However, there are additional factors that induce organic damage. Aim: To assess the association between hyperinsulinemia, ventricular hypertrophy and left ventricular diastolic function. Patients and Methods: Seventy-four [...] patients aged 30 to 65 years, with mild or moderate systemic hypertension, with overweight or mild obesity and normal glucose tolerance curve (GTC), were studied. Serum insulin was measured during GTC. The maximum levels of insulin and glucose were observed 60 minutes after the oral glucose load and they were expressed as rG/1. Patients were stratified in three groups according to their glucose and insulin fasting levels (I0) and post-glucose challenge levels (rG/I): Group 1 (normoinsulinemic patients) I0 2 (2.45+0.4). Group 2 (post-prandial hyperinsulinemic patients) I0 1 (1.34+0.3). Group 3 (persistently hyperinsulinemic patients) I0 >17 mU/mL and

The blood pressure (BP) J-curve debate started in 1979, and we still cannot definitively answer all the questions. However, available studies of antihypertensive treatment provide strong evidence for J-shaped relationships between both diastolic and systolic BP and main outcomes in the general population of hypertensive patients, as well as in high-risk populations, including subjects with coronary artery disease, diabetes mellitus, left ventricular hypertrophy, and elderly patients. However,...

Although measuring blood pressure at the bilateral brachia is common in medical practice, its clinical significance in patients with suspected coronary artery disease (CAD) has not been fully clarified. The method of this study was to define the significance of inter-arm systolic blood pressure difference in patients with suspected CAD, and to assess the relationship between inter-arm pressure difference and CAD, simultaneous brachial and ankle blood pressure measurements and stress myocardial single-photon emission computed tomography (SPECT) were performed in 386 consecutive patients with suspected CAD, excluding those with previous myocardial infarction or coronary revascularization. Subclavian artery stenosis, defined as ?15 mmHg inter-arm systolic blood pressure difference, was found in 27 patients (7%). Age (65±12 vs 65±11 years), male sex (21/27 vs 244/359), prevalence of hypertension (63% vs 56%), hypercholesterolemia (63% vs 62%), diabetes mellitus (33% vs 38%), cigarette smoking (44% vs 41%) and family history of CAD (15% vs 12%) were similar between patients with subclavian artery stenosis and those without. The incidence of decreased ankle-brachial pressure index (ABI) was higher (37% vs 12%, p=0.001), and percentage ischemic myocardium as assessed by SPECT was greater (9.0±8.5% vs 5.6±6.6%, p=0.05) in patients with subclavian artery stenosis than in those without. Furthermore, significant correlations were observed between inter-arm pressure differed between inter-arm pressure difference and percentage ischemic myocardium (r=0.13; p=0.01), and ABI (r=-0.26, p<0.0001). Among 386 patients, 283 underwent coronary angiography, and 63% of those who had inter-arm blood pressure difference had CAD. Furthermore, 83% of those CAD patients had multi-vessel CAD, which is regarded as a high-risk subset for subsequent cardiac events. Inter-arm pressure difference is often found in patients with suspected CAD, and is associated with significant CAD and peripheral artery disease. Thus, inter-arm pressure difference may be regarded as a simple marker for coronary and peripheral artery diseases. (author)

Background and objectives: Mean arterialpressure has been used in clinical trials in nephrology to randomly assign and treat patients, yet the pulsatile component of BP is recognized to influence outcomes in older people. I examined the unique contributions of systolic (SBP) and diastolic BP (DBP) on the risk for ESRD and death in patients with chronic kidney disease (CKD).